basics of computers

1. COMPUTER APPLICATIONS IN
MANAGEMENT
(For those who joined in July 2005 and after)
Time: Three hours
Maximum : 50 marks
SECTION A- (10 x 1 = 10 marks)
Answer ALL questions.
Explain the following:
1. What is software?
2. Expand ADCCP.
3. What do you mean by Electronic
Mail?
4. List out any three input devices.
5. What is Analog Signals?
6. Define constant.
7. What is the shortcut key to
underline the text?
8. What is sorting?
9. What connectivity provides direct
connection between client computer
and internet host?
10. Expand WWW.
SECTION B – (4x 5 = 20 marks)
Answer any FOUR questions.
Each question carries 5 marks.

2. 11. Explain about the temporary
storage device.
12. Give an overview of optical fiber
communication.
13. Explain the query language in
DBM packages.
14. State and explain the function in
OS.
15. How are computers classified?
16. Define and explain e-commerce.
SECTION C- (2 X 10 = 20 marks)
Answer any TWO questions.
Each question carries 10 marks
17. Write an essay on the merits and
limitations of the computer.
18. Explain the internet application
in various fields.
19. Give brief account on network
fundamentals.
_________
8524/NIE

3. 5651/N1E NOVEMBER 2007
COMPUTER APPLICATIONS IN MANAGEMENT
_______________________________________________
_
(For those who joined in July 2005 and after)
Time: Three hours Maximum: 50 marks
SECTION A – (10 x 1 = 10 marks)
Answer ALL questions.
Explain the following:
1. System.
2. Hardware.
3. End user.
4. National Language.
5. Node.
6. Short cut key for Bold the text.
7. Schema.
8. Modem.
9. DBMS.
10. Data Flow Diagram.
SECTION B – (4 x 5 = 20 marks)
Answer FOUR questions.
11. Explain the application of Spread sheets.
12. Elaborate the merits and demerits of any 3 types of
Network System.
13. Discuss the Objectives of DBMS.

4. 14. State and explain the different measures for Security in
Internet Process.
15. Explain the latest development in long distance
Computer Network Models.
16. Elaborate the application of Computer in Management.
SECTION C – (2 x 10 = 20 marks)
Answer any TWO questions
17. Define programming. Explain the steps involved in the
development of programs.
18. Write an essay on the application of E-Commerce in
Management.
19. How should an internet worked business enterprises
store, access, and distribute data and information about
the internal operations and external environment.
__________
5651/NIE
1990/N1E NOVEMBER 2005
Paper V – COMPUTER APPLICATIONS IN
MANAGEMENT
_______________________________________________
_
Time: Three hours Maximum: 50 marks
SECTION A – (10 x 1 = 10 marks)
Answer ALL questions.

5. Explain the following:
20. What is hardware?
21. What is spreadsheet?
22. List down any three output devices.
23. What is data?
24. What do you mean by Attributes?
25. CDROM is both read and write device? Say true or
false.
26. Which device converts speech into electrical form?
27. Which software reads a basic instruction, tests for
syntax, converts to machine code and executes it?
28. Expand MS-DOS.
29. Which symbol distinguish a function from a normal
entry in networks?
SECTION B – (4 x 5 = 20 marks)
Answer FOUR questions.
Each question carries 5 marks.
30. What do you mean by structured programs? And give
brief note on any one of the structured programs.

6. 31. Write an essay comparing assembly and high level
languages.
32. Differentiate schema and subschema.
33. Write short note on the function of CPU.
34. What are the various types of database that have
evolved?
35. Describe satellite communication system.
36. What are the various generations of computers?
And explain briefly.
37. Give brief account on computer networks.
38. How e-mail and its features can used? Explain
__________
1990/NIE
COMPUTER APPLICATIONS IN
MANAGEMENT
2005
Section (A)
1. Advanced Data Communication Control Procedures (ADCCP)
Advanced Data Communication Control Procedures
(ADCCP): A bit-oriented Data-Link-Layer protocol
used to provide point-to-point and point-to-multipoint
transmission of data frames that contain error-control
information. Note: ADCCP closely resembles high-level
data link control (HDLC) and synchronous data link
control (SDLC).
2. Software: Non-touchable part of computer.
• Used to describe the instructions, given to a computer.
• Program or group of programs.

7. • Computer instructions or data, anything that can be stored
electronically is software.
3:Analog signal:
• Analog signals are continuous in nature, they carry information in
the form of waves e.g., the way sound travels in the medium such
as telephone lines.
• Analog communication uses general purpose communication
channels.
• These signals are characterized by two parameters such as
amplitude and frequency
4: shortcut key to underline the text is ctrl +U
5: Email.
Email is now an essential communication tools in business. It is also excellent for
keeping in touch with family and friends. The advantages to email is that it is free (no
charge per use) when compared to telephone, fax and postal services.
6: three input devices
1. Keyboard 2.mouse 3. Light pen
7: Expand WWW
World Wide Web
WWW - An intricate web of information linked by names and associations, the World
Wide Web integrates text, video, photographs, graphics, and sound. Every site – or
homepage - on the Web has an “http” address and can be accessed using a Web browser
(e.g., Netscape). You can download information on many homepages to your own
computer. You can view text-based information on the World Wide Web using a
command line browser such as Lynx.

8. 8:Sorting: The most common type of sorting, and one that is applicable to our situation,
is alphabetical ordering. This kind of ordering places the cells that start with the early
letters of the alphabet (a, b, c...) at the top and the later letters (t, u, v...) at the bottom of
the list.
1. First we need to select all the data so we can begin to sort it. Because each name
has a corresponding score we need to select both columns to preserve the students'
correct scores.
2. Left-click and hold on cell A1 then drag down-right to cell B10 to highlight all
the data for sorting! Your spreadsheet should look like this:
3. Left-click the "sort ascending" button, located near the top, on the shortcut bar (it
has a blue A on top and a red Z on bottom with a downward pointing arrow).
9: IEEE Internet Computing,
... such agents would be behavior to provide (and interpret ... Alternately, a direct
connection
could be made between the ... back to front compared with what’s needed ...
10: Constant: define data structures ... can use the type Dx we declare
the following ... user does not need to change the definition of the function, i.e.
constant.
SECTION B

9. 11: Temporary storage device
1. Random Access Memory (RAM)
• Basic to all computers.
• In the form of integrated circuits that allow the stored data to be accessed in any
order i.e. at random and without the physical movement of the storage medium or
a physical reading head.
• Made up of several small parts known as cells.
• Each cell can store a fixed no. of bits.
• Each cell has a unique no. assigned to it which is known as address of cell.
• Also known as Read/Write memory.
• Volatile in nature.
• Usually it is known as memory of computer
Types of RAM
There are two basic types of RAM:
1. Dynamic RAM (DRAM) - The term dynamic indicates that the memory must be
constantly refreshed or it will lose its contents.
2. Static RAM (SRAM) –
• Faster and more reliable than DRAM.
• The term static is derived from the fact that it doesn't need to be refreshed
like dynamic RAM.
• It can give access times as low as 10 nanoseconds.
• Much more expensive than DRAM.
• Due to its high cost, SRAM is often used only as a memory cache.
• Cache memory - a special high-speed storage mechanism. It can be either
a reserved section of main memory or an independent high-speed storage
device.
Other Types of RAM
Other than the above basic types of RAM, there are few more newer versions –
1. FPM DRAM: Fast Page Mode DRAM, maximum data transfer rate is 176 mbps.
2. EDO DRAM: Extended data-out DRAM, maximum data transfer rate is 264
mbps.
3. SDRAM: Synchronous Dynamic RAM, maximum data transfer rate is 528 mbps.
4. DDR SDRAM: Double Data Rate SDRAM, maximum data transfer rate is 1064
mbps.
5. DDR2 SDRAM : New version of DDR RAM with higher clock frequencies.
6. RDRAM: Rambus DRAM, used for a special high speed data bus called Rambus
channel. Maximum data transfer rate is 1600 mbps.
7. Credit Card Memory: A proprietary self contained DRAM memory module that
plugs into a special slot for use in notebooks.

10. 8. PCMCIA Memory Card: Self contained DRAM memory module that plugs into a
special slot for use in notebooks. It is not a proprietary and works with any
notebook.
12: Optical fiber communication: Fiber-optic communication is a method of
transmitting information from one place to another by sending pulses of light through an
optical fiber. The light forms an electromagnetic carrier wave that is modulated to
carry information. First developed in the 1970s, fiber-optic communication systems
have revolutionized the telecommunications industry and have played a major role in the
advent of the Information Age. Because of its advantages over electrical transmission,
optical fibers have largely replaced copper wire communications in core networks in the
developed world.
The process of communicating using fiber-optics involves the following basic steps:
Creating the optical signal involving the use a transmitter, relaying the signal along the
fiber, ensuring that the signal does not become too distorted or weak, receiving the
optical signal, and converting it into an electrical signal.
Application: Optical fiber (or fibre) is a glass or plastic fiber that carries light along its
length. Fiber optics is the overlap of applied science and engineering concerned with
the design and application of optical fibers. Optical fibers are widely used in fiber-optic
communications, which permits transmission over longer distances and at higher data
rates (a.k.a "bandwidth") than other forms of communications. Fibers are used instead of
metal wires because signals travel along them with less loss, and they are also immune to
electromagnetic interference. Fibers are also used for illumination, and are wrapped in
bundles so they can be used to carry images, thus allowing viewing in tight spaces.
Specially designed fibers are used for a variety of other applications, including sensors
and fiber lasers.
Light is kept in the "core" of the optical fiber by total internal reflection. This
causes the fiber to act as a waveguide. Fibers which support many propagation paths or
transverse modes are called multi-mode fibers (MMF). Fibers which can only support a
single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a
larger core diameter, and are used for short-distance communication links and for
applications where high power must be transmitted. Single-mode fibers are used for most
communication links longer than 550 meters.
Joining lengths of optical fiber is more complex than joining electrical wire or cable.
The ends of the fibers must be carefully cleaved, and then spliced together either
mechanically or by fusing them together with an electric arc. Special connectors are
used to make removable connections.

11. 13: Query language in DBM packages:
Database Language:-
As a language is required to understand any thing, similarly to create or manipulate a
database we need to learn a language. Database language is divided into mainly 2 parts:-
1) DDL (Data definition language)
2) DML (Data Manipulation language)
Data Definition Language (DDL)
Used to specify a database scheme as a set of definitions expressed in a DDL
1. DDL statements are compiled, resulting in a set of tables stored in a special file called
a data dictionary or data directory.
2. The data directory contains metadata (data about data)
3. The storage structure and access methods used by the database system are specified by
a set of definitions in a special type of DDL called data storage and definition language
4. Basic idea: hide implementation details of the database schemes from the users
Data Manipulation Language (DML)
1. Data Manipulation is:
Retrieval of information from the database
Insertion of new information into the database
Deletion of information in the database
Modification of information in the database
2. A DML is a language which enables users to access and manipulate data. The goal is to
provide efficient human interaction with the system.
3. There are two types of DML:
Procedural: the user specifies what data is needed and how to get it
Nonprocedural: the user only specifies what data is needed
Easier for user.

12. May not generate code as efficient as that produced by procedural languages
4. A query language is a portion of a DML involving information retrieval only. The
terms DML and query language are often used synonymously.
14: OS: special system software that acts as an
intermediary between a user of a computer and the
computer hardware.
• Provides an environment in which the user can
execute programs/applications in a convenient and
efficient manner.
Functions of O/S
1. Process Management
2. Memory Management
3. Deadlock Handling
4. File Management
5. I/O Management
6. Protection & Security
7. Job scheduling
8. Interpretation of commands and instructions.
9. Co-ordination of compilers and, assembler, programs and other s/w of computer
system.
10. Production of error messages.
11. Maintenance of internal time clock and log system usage for all users.
12. Provides easy communication between the computer system and users.
13. Resource Allocator
14. Intermediary
15. Executes application software
16. Memory management
17. CPU Scheduling
15: Classification of Computers
There are 4 categories of computers-
1. Super Computer
2. Mainframe
3. Mini Computer
4. Micro Computer
Super Computer
• The highly sophisticated computer.
• The most powerful computer made till now.
• Used for very special, highly calculation-intensive tasks like scientific research,
weather forecasting, quantum mechanical physics, climate research (global
warming), molecular modeling, physical simulations (nuclear weapons), pollution
control. Major universities, military agencies and scientific research laboratories
are heavy users.
• Very expensive, priced from $ 2 million to $ 20 million.

13. • Consume huge electricity, enough to lighten about 100 houses.
• Can have hundreds of processors.
• Speed is measured in nanoseconds.
Mainframe
A mainframe has
• 1 to 16 CPUs (modern machines more)
• Memory ranges from 128 Mb over 8 Gigabyte on line RAM
• Its processing power ranges from 80 over 550 Mips
It has often different cabinets for
• Storage
• I/O
• RAM
Separate processes (program) for
• Task management
• Program management
• Job management
• Serialisation
• Catalogs
• Inter address space
• Communication
Mini Computer
• A midsized computer. In size and power, it is less than mainframes.
• Is a multiprocessing system capable of supporting from 4 to 200 users
simultaneously.
• Can handle a great amount of data
• Can support a number of terminals.
• Slower than mainframes but support as many terminals as a mainframe can.
• Lesser storage capacity.
• Used for R&D Organisations and Universities.
• Range is from $18,000 to $50,000.
Micro Computer
• Small in size.
• Single user computer.
• Much slower than the larger computers.
• Used in small businesses, homes, and school/colleges classrooms.
• Inexpensive and easy to use.
• Also called PCs in short for Personal computers
• Support multitasking.
Types of Microcomputers are –
a) Desktop – small enough to fit on a desk but are too big to carry around.

14. b) Laptop/Notebook – portable, light weight computers, can be carried around. can
store the same amount of data and having a memory of the same size as that of a
personal computer.
PDA – Personal Digital Assistant is the smallest portable computer, not bigger than a
cheque book, also known as palmtops. These are used for keeping record of phone
numbers, dates etc. These also come with touch screen or electronic pen.
16: Definition of E-Commerce from Different Perspective
1. Communications Perspective
EC is the delivery of information, products/services, or payments over the telephone
lines, computer networks or any other electronic means.
2. Business Process Perspective
EC is the application of technology toward the automation of business transactions and
work flow.
3. Service Perspective
EC is a tool that addresses the desire of firms, consumers, and management to cut
service costs while improving the quality of goods and increasing the speed of service
delivery.
4. Online Perspective
EC provides the capability of buying and selling products and information on the internet
and other online services.
Benefit of e-Commerce
• Access new markets and extend service offerings to customers
• Broaden current geographical parameters to operate globally
• Reduce the cost of marketing and promotion
• Improve customer service
• Strengthen relationships with customers and suppliers
• Streamline business processes and administrative functions
Scope of E-Commerce
• Marketing, sales and sales promotion
• Pre-sales, subcontracts, supply
• Financing and insurance
• Commercial transactions: ordering, delivery, payment
• Product service and maintenance
• Co-operative product development
• Distributed co-operative working Use of public and private services
• Business-to-administrations (e.g. customs, etc)
• Transport and logistics
• Public procurement
• Automatic trading of digital goods
• Accounting
• Dispute resolution
SECTION C
17: Merits and limitations of the computer.

15. “A computer is an electronic device, operating under the control of instructions stored in
its own memory unit that can accept data (input); process data arithmetically and
logically, produce information (output) from the processing done, and store the results for
future use
1. Fast
• Able to process data & give output in fractions of second.
• A Powerful computer is capable of executing about 3 millions
calculations/second.
2. Accurate
• In spite of its high speed, error hardly occurs as its accuracy is consistently
high enough.
3. Reliable
• The output generated by the computer is very reliable.
• But for reliable output, input should also be reliable.
4. Large Storage Capacity
It can store huge data in small storage devices.
5. Versatile
It can work upon numbers, graphics, audio, video etc. making it really versatile.
6. Works Automatically
Once the instructions in the form of program are fed, it works automatically without any
human help until the completion of that task.
7. Diligent
It never feels tired & distracted. Its performance is constant.
8. No Emotions
Computers do not have emotional, ego & psychological problems which are destructive
in nature.
9. No IQ
Computer works as a very good assistant as it has no IQ. It 100% obeys the user.
18: Internet application in various fields.
Internet

16. The internet is a network of computers linking many different types of computers all
over the world. It is a network of networks sharing a common mechanism for addressing
computers and a common set of communication protocols for communication between
two computers on the network.
Internet or a network of networks is a group of two or more networks that are:
1. Interconnected physically
2. Capable of communicating and sharing data with each other
3. Able to act together as a single network.
Utility and Role of Internet
Nowadays if you talk of any application area, the role of Internet comes. The Internet
allows people to access a vast information resource, talk to each other by email, and join
electronic news, discussion and special mailing groups. Educationally speaking, it can
open up a whole new vista for the user as well as provide access to information resources
at one’s fingertips and provide a creative outlet for those who wish to create web pages.
There are many advantages to using the Internet such as:
· Email.
Email is now an essential communication tools in business. It is also excellent for
keeping in touch with family and friends. The advantages to email is that it is free (no
charge per use) when compared to telephone, fax and postal services.
· Information Retrieval.
There is a huge amount of information available on the internet for just about every
subject known to man, ranging from government law and services, trade fairs and
conferences, market information, new ideas and technical support. Go to a search engine
and search for any subject topic. You will find a heck of material.
· Services.
Many services are now provided on the Internet such as online banking, job seeking and
applications, and hotel reservations. Often these services are not available off-line or cost
more.
· Buy or sell products.

17. The internet is a very effective way to buy and sell products all over the world. I think
you all must have heard of www.baazi.com. It is a very popular site for selling and
buying products.
Communities.
Communities of all types have sprung up on the Internet. It’s a great way to meet up with
people of similar interest and discuss common issues. An example is like chat rooms,
Electronic Bulletin Boards.
Services/Applications of Internet
Internet is an ocean of information and services. Wide variety of services remain
available on internet. Whosoever wishes, can avail these services by visiting the website.
Few popular services of internet are described below:
1. Internet telephony is a service that enables its users to communicate with other
persons. Using this service an internet user can ring other person’s normal
telephone. If other person picks up his phone, communication path b/w the two
persons gets established and they talk in the same way as two telephone users do.
This type of telephony is called Net-to-Phone telephony.
2. News group is very popular service of internet, in which a person has to become a
member of a predefined group. Each group relates to a specific topic like
multimedia, physics etc. Members of the group exchange information, news,
problems, solutions etc. among them.
Due to the categorization of group, like minded people become the members of
the group. This keeps the discussion inline and helps members in seeking
solutions for their questions and problems from other group members.
3. There are various web-sites on Internet, which provide electronic greeting cards
for all occasions and all reasons. These cards are generally very colorful,
attractive and often animated. People access these web sites and send cards to
their relatives and friends.
4. There are various web sites on Internet, which provide facility for reading
newspapers, magazines and articles on Internet.
5. Astrological web sites of internet provide horoscope, future predictions and
suggestions to the visitors, who visit the web site.
6. There are various web sites on Internet, which provide job opportunities to the
persons seeking job. They also help employers in searching the right candidate.
7. Music, songs and radio can be enjoyed over Internet.

18. 8. There are various web sites, which sell different kinds of products. These web
sites can be visited and products can be purchased from there. These web sites are
often referred to as e-mall. Payment for the purchased items is made on-line
through credit cards.
9. Numerous free and paid computer games are available on the Internet. They can
be downloaded and played.
10. Advance booking in hotels, trains, aero planes etc. can be do done through
internet.
Internet Security and protocol
As internet is open to all, the security, privacy, authenticity and anonymity issues play a
vital role as one need to be sure about these things, then only he can use the Internet to its
fullest extent. As information and its transfer are crucial for every one who is using the
internet, there need to be provisions, which is reliable then only one can connect to
internet. The security of internet can be divided into two broad categories, namely:
1. Client-Server Security
2. Data & Transaction Security
Client-Server Security
This security is for preventing unauthorized access to restricted databases and other
information which is confidential. This is an authorization mechanism, which makes it
sure that the users, who are authorized only should be able to connect and access the
information. These mechanisms are required to ensure that only authenticated users can
access the resources, which they are entitled to. Password protection, encrypted smart
cards, biometrics, firewalls etc. are some of the methods adopted to ensure client-server
security.
Data & Transaction Security
As the data transmissions and transactions occur across the network, there are fair
chances that they can be intercepted, read and manipulated as well as the source and
destination can be tracked. To prevent this one has to provide security to the data and
transactions, which is usually done by using data encryptions, which is implemented
through various cryptographic methods.
Security Methods for Client/Server & Data/Transaction Security
1. Password Scheme:
This is an easy solution to provide security, so that unauthorized users do not get
access to the data. This is the first level of security, which can be provided. Here,

19. the authorized users are assigned user names and a password is associated to
them, which are to provided when connecting to the site. But this security
measure can be broken easily, if common words or proper names are used as
passwords, but if alphanumeric passwords of bigger length are used, then it is
very difficult to break them.
Another problem is that, if the login is remote, then the password travels through
the system to server for authentication, in meantime, it can be trapped, for this
reason the passwords are to be encrypted before transmitting them.
But in spite of these threats, password schemes are still the most popular forms of
ensuring security.
2. Firewalls
Firewall is accepted as the network protection mechanism, it is a barrier between
corporate network and the outside world, which will ensure that the authentic
Users only connect as well only the data which is harmless enters and leaves the
system.
The term firewall can be defined as a device, a computer or a router which is
placed between the network and the internet to control and monitor the traffic
between the inside and outside world.
Firewall is a device which is used to shield vulnerable areas from various dangers.
The firewall system is located at a gateway point which actually is the connecting
point to the outside world. Firewalls come in many varieties and offer different
features, but the basic feature is to filter the traffic of data and control it.
3. Encryption
This method of data and transaction security is used for retaining confidentiality
and integrity of the data being transmitted. Data confidentiality is that property,
which makes data contents to be safe from being read, while on the path of
transmission, which is made sure by using cryptography algorithms for encrypting
data, which no one can interpret. Along with data being confidential, it has to
remain unmodified, while on transit i.e. the data should be intact without any
modifications, while it is on way to destination. This is made sure by using
various encryption techniques like Secret-Key Cryptography, Data Encryption
Standard(DES), Public Key Cryptography RSA etc.
Internet Tools
Here is a list of some popular Internet tools. Some of these tools we will discuss in more
detail later in this chapter.

20. · E-mail - Electronic mail is one of the most popular Internet tools. Users have their own
e-mail address and mailbox, which allow them to exchange typed messages. Some e-mail
programs allow users to send documents as attachments to their messages.
· FTP - Short for File Transfer Protocol, ftp is a method used to transfer files from one
networked computer to another. There are two ways to ftp files - privately and
anonymously. If you have a private account on a machine (e.g., bullwinkle.ucdavis.edu),
you can ftp to that machine with your login ID and password. To anonymously ftp, you
must know the host name of the computer storing the information (e.g., itcap.
ucdavis.edu). You can login by using anonymous as the ID and your e-mail address as
the password. You can then use ftp to transfer any files to your own account or hard disk.
· Newsreader - A newsreader is an application that allows you to access Usenet news.
Usenet news consists of several thousand discussion groups where people can post and
read articles about selected topics. You can subscribe to newsgroups, which interest you.
The USENET News system (or netnews) is an international deorganised system for the
dissemination of information on almost every topic. Newsgroups are divided into
hierarchies, such as:
alt - for alternate newsgroups
aus - Australian newsgroups
comp - computer related newsgroups
news - newsgroups about news
rec - recreational newsgroups
sci - scientific newsgroups
· Telnet - Telnet is a method used to connect to another computer on the Internet. This
connection is often referred to as a terminal session. You may telnet to machines that
provide access through either a private or public account.
· SLIP/PPP - Short for Serial Line Internet Protocol (SLIP)/Point to Point Protocol
(PPP), SLIP/PPP is an Internet protocol that allows dial-in access to the Internet through
a special modem pool. You can use SLIP/PPP to dial-in to the campus modem pool
(752-7925) and be connected to the Internet. While connected, you can run Netscape and
other Internet applications.
· WWW - An intricate web of information linked by names and associations, the World
Wide Web integrates text, video, photographs, graphics, and sound. Every site – or
homepage - on the Web has an “http” address and can be accessed using a Web browser
(e.g., Netscape). You can download information on many homepages to your own
computer. You can view text-based information on the World Wide Web using a
command line browser such as Lynx.
· Search Engines -The first thing most people do when they start using the WWW is to
use a search engine to try to find information. There are many very common ones. A new
one that we particular like is google.com. These have to be used with care. It often helps
if you can start searching in a sub-area of the WWW.

21. · Gopher- gopher is a tool that is very similar to the World- Wide Web. It predates the
WWW and is basically a system for the retrieval of text documents. Only a few sites
remain. It does not support graphics, a markup language or hypertext links. Any good
web browser can work with gopher sites. Specific gopher clients are no longer used
Internet Protocols
19: Computer Network
A computer network is defined as the interconnection of 2 or more independent
computers or/and peripherals.
Need of Networks
– Communicate and collaborate
– Share information
– Share resources
– Sharing computer files and disk space
– Sharing high-quality printers
– Access to common fax machines
– Access to common modems
– Multiple access to the Internet
Classification of Networks
1. Local Area Networks (LANs) - a computer network covering a small
geographic area, like a home, office, or group of buildings. Typically
within 5-mile radius.
2. Metropolitan Area Networks (MANs)- are large computer networks
usually spanning a city. (within 30 miles)
3. Wide-Area Networks (WANs) - any network whose communications
links cross metropolitan, regional, or national boundaries.
Network Topology
The way in which the computers are interconnected together is known as TOPOLOGY.
Types of physical topologies
• Bus/Linear
• Star
• Ring
• Tree
• Mesh
Linear or bus topology
• Consists of a main cable, known as backbone cable, with a terminator at each end
.
• All nodes (file server, workstations, and peripherals) are connected to the cable.
• Ethernet and LocalTalk networks use bus topology.
• Consists of a main cable, known as backbone cable, with a terminator at each end
.
• All nodes (file server, workstations, and peripherals) are connected to the cable.

22. • Ethernet and LocalTalk networks use bus topology.
• Advantages of Bus Topology
• Easy to connect a computer or peripheral to a linear bus.
• Requires less cable length.
• Easy to extend.
• If one node of the N/W is faulty, the N/W can still remain working.
Disadvantages of Bus Topology
• Entire network shuts down if there is a break in the main cable.
• Terminators are required at both ends of the backbone cable.
• Difficult to identify the problem if the entire network shuts down.
• Not meant to be used as a stand-alone solution in a large building.
Star topology
• A star topology is designed with each node (file server, workstations, and
peripherals) connected directly to a central network hub.
• Data on a star network passes through the hub before continuing to its destination.
• The hub manages and controls all functions of the network.
• It also acts as a repeater for the data flow.
Advantages of Star Topology
• Easy to install.
• No disruptions to the network other than connecting or removing devices.
• Easy to detect faults and to remove parts.
Disadvantages of Star Topology
• Requires more cable length than a bus topology.

23. • If the hub fails, nodes attached are disabled.
• More expensive than bus topology because of the cost of the hub.
Tree Topology
• A tree topology combines characteristics of bus and star topologies.
• It consists of groups of star-configured workstations connected to a bus backbone
cable.
• Tree topologies allow for the expansion of an existing network.
Advantages of a Tree Topology
• Point-to-point wiring for individual segments.
• Supported by several hardware and software venders.
Disadvantages of Tree Topology
• Overall length of each segment is limited by the type of cabling used.
• If the backbone line breaks, the entire segment goes down.
• More difficult to configure than other topologies.
Ring topology
• Is a type of computer network configuration where each network computer and
device are connect to each other forming A large circle.
• Data is divided into packets when transmitted.
• Packet is sent around the ring until it reaches its final destination.

24. Advantages of ring topology
• Requires lesser amount of cable and there are not much of installation problems
• All stations have equal access
Disadvantages of ring topology
• Failure of one computer may impact others
• Data transfer is slow
Mesh topology
• It requires that every terminal should be attached to each other.
• All the computers must have adequate number of interfaces for the connections to
be made.
• Because of this requirement the installations is somewhat difficult.
• The length of cable required is quite higher as compared to other topologies
Advantages of mesh topology
• Ease of troubleshooting.
• Data transfer is faster.
Disadvantages of mesh topology
• uses a lot of cabling.
• Complex
• Most expensive topology

25. Nov 2005
1. Hardware: Hardware refers to the physical components of a computer system including any
peripheral (I/O) equipment such as keyboard , printers, modems and mouse etc.
2. Spreadsheet: A table of values arranged in rows and columns. Each value can have a
predefined relationship to the other values. If you change one value, therefore, you may need
to change other values as well.
3. Any three Output Devices: printer, plotter, monitor
4. Data: Data refers to a collection of facts usually collected as the result of experience,
observation or experiment, or processes within a computer system, or a set of
premises. This may consist of numbers, words, or images, particularly as
measurements or observations of a set of variables. Data is often viewed as a lowest
level of abstraction from which information and knowledge are derived.
5. Attributes: In computing, an attribute is a specification that defines a property of an object,
element, or file. An attribute of an object usually consists of a name and a value; of an
element, a type or class name; of a file, a name and extension.
6. False, CD-ROM (an initialism of "Compact Disc Read-Only Memory") is a pre-pressed
Compact Disc that contains data accessible to, but not writable by, a computer.
7. Transducer is the device which converts speech into electrical form.
8. Compiler
9. MS-DOS: Microsoft Disk Operating System
MS-DOS (short for Microsoft Disk Operating System) is an operating system
commercialized by Microsoft. It was the most commonly used member of the DOS

26. family of operating systems and was the main operating system for personal computers
during the 1980s. It was based on the Intel 8086 family of microprocessors, particularly
the IBM PC and compatibles. It was gradually replaced on consumer desktop computers
by operating systems offering a graphical user interface (GUI), in particular by various
generations of the Microsoft Windows operating system and Linux. MS-DOS was
known before as QDOS (Quick and Dirty Operating System) and 86-DOS.
10.
11. Structured Programs: Structured programming can be seen as a subset or
subdiscipline of procedural programming, one of the major programming paradigms.
It is most famous for removing or reducing reliance on the GOTO statement.
Historically, several different structuring techniques or methodologies have been
developed for writing structured programs. The most common are:
1. Edsger Dijkstra's structured programming, where the logic of a program is a
structure composed of similar sub-structures in a limited number of ways. This
reduces understanding a program to understanding each structure on its own, and
in relation to that containing it, a useful separation of concerns.
2. A view derived from Dijkstra's which also advocates splitting programs into sub-
sections with a single point of entry, but is strongly opposed to the concept of a
single point of exit.
3. Data Structured Programming or Jackson Structured Programming, which
is based on aligning data structures with program structures. This approach
applied the fundamental structures proposed by Dijkstra, but as constructs that
used the high-level structure of a program to be modeled on the underlying data
structures being processed. There are at least 3 major approaches to data
structured program design proposed by Jean-Dominique Warnier, Michael A.
Jackson, and Ken Orr.
The two latter meanings for the term "structured programming" are more common,
and that is what this article will discuss. Years after Dijkstra (1969), object-oriented
programming (OOP) was developed to handle very large or complex programs (see
below: Object-oriented comparison).

27. Low-level structure
At a low level, structured programs are often composed of simple, hierarchical
program flow structures. These are sequence, selection, and repetition:
• "Sequence" refers to an ordered execution of statements.
• In "selection" one of a number of statements is executed depending on the state of
the program. This is usually expressed with keywords such as if..then..else..endif,
switch, or case.
• In "repetition" a statement is executed until the program reaches a certain state or
operations are applied to every element of a collection. This is usually expressed
with keywords such as while, repeat, for or do..until. Often it is recommended
that each loop should only have one entry point (and in the original structural
programming, also only one exit point), and a few languages enforce this.
Some languages, such as Dijkstra's original Guarded Command Language,
emphasise the unity of these structures with a syntax which completely encloses the
structure, as in if..fi. In others, such as C, this is not the case, which increases the risk of
misunderstanding and incorrect modification.
A language is described as "block-structured" when it has a syntax for enclosing
structures between bracketed keywords, such as an if-statement bracketed by if..fi as in
ALGOL 68, or a code section bracketed by BEGIN..END, as in PL/I. However, a
language is described as "comb-structured" when it has a syntax for enclosing structures
within an ordered series of keywords. A "comb-structured" language has multiple
structure keywords to define separate sections within a block, analogous to the multiple
teeth or prongs in a comb separating sections of the comb. For example, in Ada, a block
is a 4-pronged comb with keywords DECLARE, BEGIN, EXCEPTION, END, and the if-
statement in Ada is a 4-pronged comb with keywords IF, THEN, ELSE, END IF.
12. High Level Languages: a high-level programming language is a programming
language with strong abstraction from the details of the computer. In comparison to
low-level programming languages, it may use natural language elements, be easier to
use, or more portable across platforms. Such languages hide the details of CPU
operations such as memory access models and management of scope.
This greater abstraction and hiding of details is generally intended to make the
language user-friendly, as it includes concepts from the problem domain instead of
those of the machine used. A high level language isolates the execution semantics of a
computer architecture from the specification of the program, making the process of
developing a program simpler and more understandable with respect to a low-level

28. language. The amount of abstraction provided defines how 'high level' a programming
language is.
Assembly Languages: An assembly language is a low-level language for
programming computers. It implements a symbolic representation of the numeric
machine codes and other constants needed to program a particular CPU architecture.
This representation is usually defined by the hardware manufacturer, and is based on
abbreviations (called mnemonics) that help the programmer remember individual
instructions, registers, etc. An assembly language is thus specific to a certain physical or
virtual computer architecture (as opposed to most high-level languages, which are
usually portable).
Assembly languages were first developed in the 1950s, when they were referred to as
second generation programming languages. They eliminated much of the error-prone
and time-consuming first-generation programming needed with the earliest computers,
freeing the programmer from tedium such as remembering numeric codes and calculating
addresses. They were once widely used for all sorts of programming. However, by the
1980s (1990s on small computers), their use had largely been supplanted by high-level
languages, in the search for improved programming productivity. Today, assembly
language is used primarily for direct hardware manipulation, access to specialized
processor instructions, or to address critical performance issues. Typical uses are device
drivers, low-level embedded systems, and real-time systems.
A utility program called an assembler is used to translate assembly language
statements into the target computer's machine code. The assembler performs a more or
less isomorphic translation (a one-to-one mapping) from mnemonic statements into
machine instructions and data. (This is in contrast with high-level languages, in which a
single statement generally results in many machine instructions. This is done by one of
two means: a compiler is used to most-efficiently translate high-level language
statements into machine code "executable" files; an interpreter executes similar
statements directly and in its own application environment.)
13. Schema: The schema is the physical arrangement of the data as it appears in the
DBMS.
Schema: Represents the complete description of the database
Subschema: The subschema is the logical view of the data as it appears to the application
program.
Subschema - subset of schema, application view of the database.
14. Functions of a CPU:

29. • The CPU unifies the system.
• It controls the functions performed by the other components.
• The CPU must be able to fetch instructions from memory, decode their
binary contents and execute them.
• It must also be able to reference memory and 1/0 ports as necessary in
the execution of instructions.
• In addition, the CPU should be able to recognize and respond to
certain external control signals, such as INTERRUPT and WAIT
requests.
• CPU controls the system buses.
• It schedules timing for computer processes
• CPU accepts input
• It executes instructions
• It directs other components of the computer
15. Types of Databases:
There are primarily two types: analytical databases and operational databases.
Analytic Databases
Analytic databases (a.k.a. OLAP- On Line Analytical Processing) are primarily
static, read-only databases which store archived, historical data used for analysis. For
example, a company might store sales records over the last ten years in an analytic
database and use that database to analyze marketing strategies in relationship to
demographics.
Operational Databases
Operational databases (a.k.a. OLTP On Line Transaction Processing), on the other
hand, are used to manage more dynamic bits of data. These types of databases allow
you to do more than simply view archived data. Operational databases allow you to
modify that data (add, change or delete data).
These types of databases are usually used to track real-time information. For
example, a company might have an operational database used to track warehouse/stock
quantities. As customers order products from an online web store, an operational
database can be used to keep track of how many items have been sold and when the
company will need to reorder stock.
Database Models
Besides differentiating databases according to function, databases can also be

30. differentiated according to how they model the data.
What is a data model?
A data model is a "description" of both a container for data and a methodology for
storing and retrieving data from that container. Actually, there isn't really a data model
"thing". Data models are abstractions, oftentimes mathematical algorithms and
concepts. You cannot really touch a data model. But nevertheless, they are very useful.
The analysis and design of data models has been the cornerstone of the evolution of
databases. As models have advanced so has database efficiency.
Before the 1980's, the two most commonly used Database Models were the
hierarchical and network systems. Let's take a quick look at these two models and then
move on to the more current models.
Hierarchical Databases
As its name implies, the Hierarchical Database Model defines hierarchically-
arranged data.
The most intuitive way to visualize this type of relationship is by visualizing an
upside down tree of data. In this tree, a single table acts as the "root" of the database
from which other tables "branch" out.
You will be instantly familiar with this relationship because that is how all
windows-based directory management systems (like Windows Explorer) work these
days.
Relationships in such a system are thought of in terms of children and parents such
that a child may only have one parent but a parent can have multiple children. Parents
and children are tied together by links called "pointers" (perhaps physical addresses
inside the file system). A parent will have a list of pointers to each of their children.
This child/parent rule assures that data is systematically accessible. To get to a low-
level table, you start at the root and work your way down through the tree until you
reach your target. Of course, as you might imagine, one problem with this system is

31. that the user must know how the tree is structured in order to find anything!
The hierarchical model however, is much more efficient than the flat-file model
because there is not as much need for redundant data. If a change in the data is
necessary, the change might only need to be processed once. Consider the student flat
file database example from our discussion of what databases are:
Name Address Course Grade
Mr. Eric Tachibana 123 Kensigton Chemistry 102 C+
Mr. Eric Tachibana 123 Kensigton Chinese 3 A
Mr. Eric Tachibana 122 Kensigton Data Structures B
Mr. Eric Tachibana 123 Kensigton English 101 A
Ms. Tonya Lippert 88 West 1st St. Psychology 101 A
Mrs. Tonya Ducovney 100 Capitol Ln. Psychology 102 A
Ms. Tonya Lippert 88 West 1st St. Human Cultures A
Ms. Tonya Lippert 88 West 1st St. European Governments A
As we
mentioned before, this flat-file database would store an excessive amount of redundant
data. If we implemented this in a hierarchical database model, we would get much less
redundant data. Consider the following hierarchical database scheme:
However, as you can imagine, the hierarchical database model has some serious
problems. For one, you cannot add a record to a child table until it has already been
incorporated into the parent table. This might be troublesome if, for example, you
wanted to add a student who had not yet signed up for any courses.
Worse, yet, the hierarchical database model still create repetition of data within the
database. You might imagine that in the database system shown above, there may be a
higher level that includes multiple courses. In this case, there could be redundancy
because students would be enrolled in several courses and thus each "course tree"
would have redundant student information.

32. Redundancy would occur because hierarchical databases handle one-to-many
relationships well but do not handle many-to-many relationships well. This is because a
child may only have one parent. However, in many cases you will want to have the
child be related to more than one parent. For instance, the relationship between student
and class is a "many-to-many". Not only can a student take many subjects but a subject
may also be taken by many students. How would you model this relationship simply
and efficiently using a hierarchical database? The answer is that you wouldn't.
Though this problem can be solved with multiple databases creating logical links
between children, the fix is very kludgy and awkward.
Faced with these serious problems, the computer brains of the world got together
and came up with the network model.
Network Databases
In many ways, the Network Database model was designed to solve some of the
more serious problems with the Hierarchical Database Model. Specifically, the
Network model solves the problem of data redundancy by representing relationships in
terms of sets rather than hierarchy. The model had its origins in the Conference on Data
Systems Languages (CODASYL) which had created the Data Base Task Group to
explore and design a method to replace the hierarchical model.
The network model is very similar to the hierarchical model actually. In fact, the
hierarchical model is a subset of the network model. However, instead of using a
single-parent tree hierarchy, the network model uses set theory to provide a tree-like
hierarchy with the exception that child tables were allowed to have more than one
parent. This allowed the network model to support many-to-many relationships.
Visually, a Network Database looks like a hierarchical Database in that you can see
it as a type of tree. However, in the case of a Network Database, the look is more like
several trees which share branches. Thus, children can have multiple parents and
parents can have multiple children.

33. Nevertheless, though it was a dramatic improvement, the network model was far
from perfect. Most profoundly, the model was difficult to implement and maintain.
Most implementations of the network model were used by computer programmers
rather than real users. What was needed was a simple model which could be used by
real end users to solve real problems.
Relational Databases
In a relational database, data elements are organized as multiple tables with rows and
columns. Each table is stored as a separate file. Each table column represents a data
field and each row a data record. Data in one table is related to data in another table
with a common field.
Relational model provides greater flexibility of data organization and future
enhancements in database as compared to hierarchical and network models.
s.no Name Age Date of salary
joining
1 Anuj 25 2-dec-1989 10,000
2 Bharat 27 4-july-1999 12,000
3 Sunny 25 3-june-1990 13,000
Object Oriented Databases:
Object-oriented database model was introduced to overcome the shortcomings of
conventional database models. An object-oriented database is a collection of objects
whose behaviour, state and relationships are defined in accordance with object-oriented
concepts.
15. Satellite Communication System:

34. Satellite communication systems consist of Earth-orbiting communications platforms
that receive and retransmit signals from earth-based stations. A typical television satellite
receives a signal from a base station and broadcasts it to a large number of terrestrial
receivers. Signals to satellites are called "uplinks," and signals from satellites are called
"downlinks." Uplinks have also been called "shooting the bird." The downlink covers an
area called the "footprint," which may be very large or cover a focused area. Satellites use
microwave frequencies. Since they are overhead, the transmissions are line of sight to the
receiver.
The most common frequency bands for satellites are listed here.
Band Uplink Downlink
L/S 1.610 to 1.625 GHz 2.483 to 2.50 GHz
C 3.7 to 4.2 GHz 5.924 to 6.425 GHz
Ku 11.7 to 12.2 GHz 14.0 to 14.5 GHz
Ka 17.7 to 21.7 GHz 27.5 to 30.5 GHz
As pictured in Figure S-2, there are "high-orbit" GEO (geosynchronous satellites),
"low-orbit" LEO (low earth orbit) satellites, and satellites in a variety of mid-orbits and
elliptical orbits (some spy satellites use these orbits so they can drop in for a close look).
Geosynchronous satellites are placed in high stationary orbits 22,300 miles (42,162
kilometers) above the earth. The satellites are typically used for video transmissions. The
speed and height of these satellites allow them to stay synchronized above a specific
location on the earth at all times. One problem with high-orbit geosynchronous satellites
is that a typical back-and-forth transmission has a delay of about a half second, which
causes problems in time-critical computer data transmissions, as discussed in a moment.
Satellites in LEO orbit are low enough to minimize this problem.
LEOs are close to the earth, usually within a few hundred kilometers, and inclined to
the equatorial plane. Since the satellites are near the earth, earth-based devices don't
require as much power to communicate with the satellites. Thus, they are ideal for phones
and hand-held devices. However, LEOs are in fast orbits and do not stay stationary above
a point on the earth. Therefore, a country-wide or global communication system requires
a constellation of satellites that basically project moving footprints above the earth. As
one satellite moves out of position, another takes over coverage. Calls and other
transmissions are handed off from one satellite to another in this process. This is just the
opposite of cellular phone systems where people move in and out of cells.

35. There is debate about which system is better for data communications: GEO or LEO.
While LEOs are ideal for mobile wireless devices, the current trend is to enable GEOs
with more bandwidth. Still, the delay of GEOs is a problem for time-critical applications.
17. Generations of Computers:
The Five Generations of Computers
The history of computer development is often referred to in reference •
to the different generations of computing devices. Each generation of
computer is characterized by a major technological development that
fundamentally changed the way computers operate, resulting in
increasingly smaller, cheaper, more powerful and more efficient and
reliable devices.
Read about each generation and the developments that led to the current
devices that we use today.
First Generation - 1940-1956: Vacuum Tubes
The first computers used vacuum tubes for circuitry and magnetic
drums for memory, and were often enormous, taking up entire rooms.
They were very expensive to operate and in addition to using a great
deal of electricity, generated a lot of heat, which was often the cause of
malfunctions.
First generation computers relied on machine language, the lowest-
level programming language understood by computers, to perform
operations, and they could only solve one problem at a time. Input was
based on punched cards and paper tape, and output was displayed on
printouts.
The UNIVAC and ENIAC computers are examples of first-
generation computing devices. The UNIVAC was the first commercial
computer delivered to a business client, the U.S. Census Bureau in
1951.
Second Generation - 1956-1963: Transistors
Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor
was invented in 1947 but did not see widespread use in computers until the late 50s. The transistor was
far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-
efficient and more reliable than their first-generation predecessors. Though the transistor still generated a
great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum

36. tube. Second-generation computers still relied on punched cards for input and printouts for output.
Second-generation computers moved from cryptic binary machine language to symbolic, or assembly,
languages, which allowed programmers to specify instructions in words. High-level programming
languages were also being developed at this time, such as early versions of COBOL and FORTRAN.
These were also the first computers that stored their instructions in their memory, which moved from a
magnetic drum to magnetic core technology.
The first computers of this generation were developed for the atomic energy industry.
Third Generation - 1964-1971: Integrated Circuits
The development of the integrated circuit was the hallmark of the third generation of computers.
Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically
increased the speed and efficiency of computers.
Instead of punched cards and printouts, users interacted with third generation computers through
keyboards and monitors and interfaced with an operating system, which allowed the device to run
many different applications at one time with a central program that monitored the memory. Computers
for the first time became accessible to a mass audience because they were smaller and cheaper than their
predecessors.
Fourth Generation - 1971-Present: Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits
were built onto a single silicon chip. What in the first generation filled an entire room could now fit in
the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the
computer - from the central processing unit and memory to input/output controls - on a single chip.
In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the
Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of
life as more and more everyday products began to use microprocessors.
As these small computers became more powerful, they could be linked together to form networks, which
eventually led to the development of the Internet. Fourth generation computers also saw the development
of GUIs, the mouse and handheld devices.
Fifth Generation - Present and Beyond: Artificial Intelligence
Fifth generation computing devices, based on artificial intelligence, are still in development, though
there are some applications, such as voice recognition, that are being used today. The use of parallel
processing and superconductors is helping to make artificial intelligence a reality. Quantum
computation and molecular and nanotechnology will radically change the face of computers in years to
come. The goal of fifth-generation computing is to develop devices that respond to natural language
input and are capable of learning and self-organization.

37. For more details please refer to the classroom notes.
18. Computer Networks: Already discussed in previous paper.

38. 19. E-mail: It can take days to send a letter across the country and weeks to go around
the world. To save time and money, more and more people are relying on electronic mail.
It's fast, easy and much cheaper than the using the postal service.
What is e-mail? In its simplest form, e-mail is an electronic message sent from one
device to another. While most messages go from computer to computer, e-mail can also
be sent and received by mobile phones, PDAs and other portable devices. With e-mail,
you can send and receive personal and business-related messages with attachments, such
as photos or formatted documents. You can also send music, video clips and software
programs.
Let's say you have a small business with sales reps working around the country. How
do you communicate without running up a huge phone bill? Or what about keeping in
touch with far-flung family members? E-mail is the way to go. It's no wonder e-mail has
become the the Internet's most popular service.
Follow the Trail
Just as a letter makes stops at different postal stations along the way to its final
destination, e-mail passes from one computer, known as a mail server, to another as it
travels over the Internet. Once it arrives at the destination mail server, it's stored in an
electronic mailbox until the recipient retrieves it. This whole process can take seconds,
allowing you to quickly communicate with people around the world at any time of the
day or night.
Sending and Receiving Messages
To receive e-mail, you need an account on a mail server. This is similar to having a
postal box where you receive letters. One advantage over regular mail is that you can
retrieve your e-mail from any location on earth, provide that you have Internet access.
Once you connect to your mail server, you download your messages to your computer or
wireless device, or read them online.
To send e-mail, you need a connection to the Internet and access to a mail server that
forwards your mail. The standard protocol used for sending Internet e-mail is called
SMTP, short for Simple Mail Transfer Protocol. It works in conjunction with POP--
Post Office Protocol--servers. Almost all Internet service providers
and all major online services
offer at least one e-mail address with every account.
When you send an e-mail message, your computer routes it to an SMTP server. The
server looks at the e-mail address (similar to the address on an envelope), then forwards it
to the recipient's mail server, where it's stored until the addressee retrieves it. You can
send e-mail anywhere in the world to anyone who has an e-mail address.

39. At one time, you could only send text messages without attachments via the Internet.
With the advent of MIME, which stands for Multipurpose Internet Mail Extension,
and other types of encoding schemes, such as UUencode, you can also send formatted
documents, photos, audio and video files. Just make sure that the person to whom you
send the attachment has the software capable of opening it.