2. Internet
The internet is a network of computers
linking many different types of
computers all overthe world.
It is a very large wide area network
(WAN) connecting computers and
networks around the world.
It makes it possible for millions of users to
connect to one another via telephone
lines, cable lines and satellites.
4. Origin of Internet
• 1969 Department of Defense (DOD) of USA started an
network called ARPANET (Advanced Research Projects
Administration Network) with one computer at California
and three at Utah.
• Later on other universities and R & D institutions were
allowed to connect to the network
• After that it is divided into two part MILNET for managing
military sites and ARPANET for managing non-military
sites.
• In 1980, NSFNET (National Science Foundation Network)
was created
• By the 1990 many computer were looking up to NSFNET
giving birth to Internet
5. InternetApplications
On-linecommunication
Software sharing
Exchangeof viewson topics of common
interest
Posting of information of generalinterset
Productpromotion
Feedback about product
Customersupport service
On-line journals andmagazines
6. InternetCharacteristic
Global Nature
Widely used
International in scope
Dynamic
Accessibility
Anonymity (Hidden User Identity)
Expanding exponentially
7. InternetCharacteristic
Anonymity
Internet users do not have to reveal their
true identity in order to send email or post
messages on bulletin boards. Users are able
to communicate and make such postings
anonymously or under assumed names.
8. InternetServices
Internet Services allows us to access huge
amount of information such as text,
graphics, sound and software over the
internet. Following diagram shows the four
different categories of Internet Services.
9. InternetServices
Communication Services
Electronic Mail
Newsgroup
Information Retrieval Services
File Transfer Protocol (FTP)
Enable the users to transfer files
Web Services
Web services allow exchange of information
between applications on the web. Using web
services, applications can easily interact with each
other.
World Wide Web (WWW)
It offers a way to access documents spread over the
several servers over the internet.
10. Element ofInternet
A simplified hierarchical model of the
internet include client PCs, Server
computers & network
Clients, Server & Networks
Clients PCs- These are the computers that
request information from servers
Server computer- a server is a computer
that holds the files for one or more web
sites
11. Element ofInternet
Networks- these are
composed with one or more
server computer and multiple
client servers
Nodes- are generic term used
to describe a client, server or
network
12. Uniform Resourcelocators
A URL (Uniform Resource Locator), as the
name suggests, provides a way to locate a
resource on the web, the hypertext system
that operates over the internet.
A URL is the most common type of Uniform
Resource Identifier (URI). URIs are strings
of characters used to identify a resource
over a network.
13.
14. InternetProtocol
The Internet Protocol (IP) is the method
or protocol by which data is sent from one
computer to another on the Internet.
Each computer (known as a host) on the
Internet has at least one IP address that
uniquely identifies it from all other computers
on the Internet.
Internet Protocol (IP) is the principal set (or
communications protocol) of digital message
formats and rules for exchanging messages
between computers across a single network or
a series of interconnected networks
15. World WideWeb
The World Wide Web (WWW), also
called the Web, is an information
space where documents and other web
resources are identified by Uniform
Resource Locators (URLs), interlinked
by hypertext links, and accessible via
the Internet.
16. Hypertext
Hypertext is text which is not constrained to be
linear.
Hypertext is text which contains links to other
texts
Hypertext is the organization of information
units into connected associations that a user
can choose to make.
Hypertext was the main concept that led to the
invention of the World Wide Web, which is,
after all, nothing more (or less) than an
enormous amount of information content
connected by an enormous number of
hypertext links.
17. Hyperlinks
A hyperlink is an icon, graphic, or text in a
document that links to another file or
object. The World Wide Web is comprised of
hyperlinks linking trillions of pages and
files to one another.
Three type of hyperlink
Text hyperlink
Image hyperlink
Image map(contains ,multiple hyperlink)
18. Elements ofWeb
WEB BROWSER- A web browser is a software
program that allows a user to locate, access, and
display web pages.
web browser, a browser is a software
application used to locate, retrieve and display
content on the World Wide Web,
including webpages, images, video and other files.
Example -Google Chrome, Mozilla Firefox, Apple
Safari
As a client/server model, the browser is
the client run on a computer or mobile device that
contacts the Web server and requests information.
The web server sends the information back to the
browser which displays the results on the
Internet-enabled device that supports a browser.
19. Elements ofWeb
A website is a collectionof
related web pages,
including multimedia content,
typically identified with a
common domain name, and
published on at least one web server.
Web Page-a hypertext document
connected to the World Wide Web.
21. Basic internetterminology
Modem-A Modem (made of Modulator&
Demodulator) is a device that converts data
from digital computer signals to analogue
signals that are generally ,sent over a phone
line.
IIS(internet information server)
Internet Information Services (IIS) is a flexible,
general-purpose web server from Microsoft that runs
on Windows systems to serve requested HTML pages
or files.
22. Basic internetterminology
TCP-
Transmission Control Protocol is a standard that
defines how to establish and maintain a network
conversation via which application programs can
exchange data.
TCP works with the Internet Protocol (IP), which
defines how computers send packets of data to
each other.
ISP-
An Internet service provider (ISP) is an
organization that provides services for accessing,
using, or participating in the Internet.
23. NETIQUETTE
Netiquette is a combination of the
words network and etiquette and is defined as
a set of rules for acceptable online behavior.
Similarly, online ethics focuses on the
acceptable use of online resources in an online
social environment.
Netiquette represents the importance of
proper manners and behavior online.
In general, netiquette is the set of professional
and social etiquettes practiced and advocated
in electronic communication over any
computer network.
24. Commerce of theinternet
E-commerce -- electronic commerce or EC --
is the buying and selling of goods and
services, or the transmitting of funds or
data, over an electronic network, primarily
the internet.
These business transactions occur either as
Business-to-business,
Business-to-consumer,
Digital Middleman
27. Crime on / through the internet
Cyber crime
criminal activities carried out by means of
computers or the Internet.
Cybercrime is defined as a crime in which a
computer is the object of the crime
(hacking, phishing, spamming) or is used as
a tool to commit an offense
28. Reasons For CyberCrime
Easy to access – The problem behind safeguarding a
computer system from unauthorized access is that
there are many possibilities of breach due to the
complex technology. Hackers can steal access codes,
retina images, advanced voice recorders etc. that can
fool biometric systems easily and bypass firewalls
can be utilized to get past many security systems.
Capacity to store data in comparatively small
space – The computer has the unique characteristic
of storing data in a very small space. This makes it a
lot easier for the people to steal data from any other
storage and use it for own profit.
29. Reasons For CyberCrime
Complex – The computers run on operating systems
and these operating systems are programmed of
millions of codes. The human mind is imperfect, so
they can do mistakes at any stage. The cyber criminals
take advantage of these gaps.
Negligence – Negligence is one of the characteristics in
human conduct. So, there may be a possibility that
protecting the computer system we may make any
negligence which provides a cyber-criminal the access
and control over the computer system.
Loss of evidence – The data related to the crime can
be easily destroyed. So, Loss of evidence has become a
very common & obvious problem which paralyses the
system behind the investigation of cyber-crime.
30. Mode and Manner OfCommitting
Cyber Crime
Unauthorized access to computer
systems or networks-This activity is
commonly referred to as hacking.
Theft of information-This includes
information stored in computer hard disks,
removable storage media etc.
Email Bombing-Email bombing refers to
sending a large number of emails to the
victim resulting in the victim's email
account or mail servers crashing.
31. Mode and Manner OfCommitting
Cyber Crime
Data Diddling-This kind of attack involves altering raw data
just before it is processed by a computer and then changing it
back after the processing is completed. Electricity Boards in
India have been victims to data diddling programs inserted
when private parties were computerizing their systems.
Salami Attacks-These attacks are used for the commission of
financial crimes. The key here is to make the alteration so
insignificant that in a single case it would go completely
unnoticed, e.g. a bank employee inserts a program, into the
bank's servers, that deducts a small amount of money, say Rs.
10 a month, from the account of every customer. No account
holder will probably notice this unauthorized debit, but the
bank employee will make a sizable amount of money every
month.
32. Mode and Manner OfCommitting
Cyber Crime
Denial of Service (DoS) Attack-This
involves flooding a computer resource with
more requests than it can handle. This
causes the resource, e.g. a web server, to
crash thereby denying authorized users the
service offered by the resource
Virus/Worm Attacks
Logic Bombs
Trojan Attacks
33. Prevention of CyberCrime
Use a full-service internet security
suite
Use strong passwords
Keep your software updated
Manage your social media settings
Strengthen your home network
Use of firewalls may be
advantageous.