Software is a set of instructions, data or programs used to operate computers and execute specific tasks. It is the opposite of hardware, which describes the physical aspects of a computer. Software is a generic term used to refer to applications, scripts and programs that run on a device.

1. CHAPTER - 3
BASIC SOFTWARE
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2. OUTCOMES OF THIS CHAPTER
 Understand the basics Software,
 Analyze various Software,
 Able to protect computer from Virus,
 Functions and types of Operating System
 Operating systems for mobile device
 Introduction with different kind of Web
Browsers 2
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3. WHAT IS SOFTWARE?
 The term Software is used to refer to the
computer programs, which is a set of
instructions that tells the computer what to do.
 Computer software is non-tangible, contrasted
with computer hardware.
 Computer software includes computer
programs, libraries and their associated
documentation.
 The word software is also sometimes used in a
more narrow sense, meaning application only.
 Example: OS, Antivirus, computer games etc. 3
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4. TYPES OF SOFTWARE:
There are two main types of software:
1. Systems Software.
2. Application Software.
1. System Software:
⚫ Is computer software designed to operate and control
the computer hardware and to provide a platform for
running application software.
System Software can be separated into two different
categories:
 Operating System Software
 Utility Software.
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5. TYPES OF SOFTWARE:
 Operating System Software:
⚫ An Operating System Software is the most
important system software that runs on a computer.
⚫ It manages the computer's memory, processes, and all of
its software and hardware.
⚫ It also allows you to communicate with the computer
without knowing how to speak the computer's language.
⚫ Without an operating system, a computer is useless.
⚫ Modern operating systems use a graphical user
interface or GUI.
⚫ Example: Microsoft Windows, Apple Mac OS X, and
Linux.
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6. TYPES OF SOFTWARE:
 Utility software :
⚫ Utility Software helps to analyze, configure, optimize and
maintain the computer, such as virus protection.
⚫ Example: Antivirus Software.
2. Applications Software:
⚫ Application Software is a program or group of programs
designed for end user to perform a group of coordinated
functions, tasks, or activities.
⚫ Application software cannot run on itself but is dependent
on system software to execute.
⚫ Examples of an application include a word processor, a
spreadsheet design and management system, an
aeronautical flight simulator, a console game, a drawing,
painting, and illustrating system, or a library management
system.
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7. MAIN PARTS OF THE OPERATING SYSTEM
The main parts of the operating system can be
divided into 4 parts:
 The Kernel
 Device Drivers
 User Interface
 System Utilities
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8. Types of operating systems
• Single- and multi-tasking:
• A single-tasking system can only run one
program at a time. Ex- Palm OS.
• while a multi-tasking operating system allows
more than one program to be running in
concurrency. This is achieved by time-sharing,
dividing the available processor time between
multiple processes. Ex- Linux, Solaris, Mac OS,
windows etc.
• Single- and multi-user:
• Single-user operating systems have no facilities
to distinguish users, but may allow multiple
programs to run in same time. Ex- Palm OS,
MS DOS etc.
• Processes and resources, such as disk space,
belonging to multiple users, and the system
permits multiple users to interact with the
system at the same time. Ex- Unix server OS.
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9. Types of operating systems (Contd.)
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• Distributed:
• A distributed operating
system manages a group of distinct
computers and makes them appear to
be a single computer. The
development of networked computers
that could be linked and communicate
with each other. Ex- LOCUS (Distributed
OS based on UNIX).
• Templated:
• In an OS, distributed and cloud
computing context, templating refers
to creating a single virtual machine
image as a guest operating system,
then saving it as a tool for multiple
running virtual machines. The
technique is used both in
virtualization and cloud computing
management, and is common in large
server warehouses.
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10. Types of operating systems (Contd.)
• Embedded:
• Embedded operating systems are
designed to be used in embedded
computer systems. They are
designed to operate on small
machines like PDAs with less
autonomy. They are able to
operate with a limited number of
resources.
• Windows CE and Minix 3 are
some examples of embedded
operating systems.
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11. Types of operating systems (Contd.)
• Real-time:
• A real-time operating system is an operating system that guarantees to
process events or data within a certain short amount of time. A real-time
operating system may be single- or multi-tasking, but when multitasking, it
uses specialized scheduling algorithms so that a deterministic nature of
behavior is achieved.
• Often used as a control device in a dedicated application such as controlling
scientific experiments, medical imaging systems, industrial control systems,
and some display systems.
• Real-Time systems may be either hard or soft real-time.
• Hard real- time means you must absolutely hit every deadline. Very
few systems have this requirement. Some examples are nuclear
systems, some medical applications such as pacemakers, a large
number of defense applications .
• Soft real-time Firm real time systems can miss some deadlines, but
eventually performance will degrade if too many are missed. A good
example is the sound system in your computer. If you miss a few bits,
no big deal, but miss too many and you're going to eventually degrade
the system.
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12. THE FUNCTIONS OF OPERATING SYSTEM:
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? Booting the computer.
? Performs basic computer tasks eg managing the
various peripheral devices eg mouse, keyboard
? Provides a user interface, e.g. command line,
graphical user interface (GUI)
? Handles system resources such as computer's
memory and sharing of the central processing unit
(CPU) time by various applications or peripheral
devices.
? Provides file management which refers to the way
that the operating system manipulates, stores,
retrieves and saves data.
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13. OPERATING SYSTEMS FOR MOBILE DEVICES
? Android OS (Google Inc.):
The Android mobile
operating system is
Google's open and free
software stack that includes
an operating system,
middleware and also key
applications for use on mobile
devices, including smart
phones.
? Bada (Samsung
Electronics): Bada is
a proprietary Samsung mobil
e OS that was first launched
in 2010. The Samsung Wave
was the first Smartphone to
use this mobile OS. 13
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14. OPERATING SYSTEMS FOR MOBILE DEVICES
? iPhone OS / iOS (Apple):
Apple's iPhone OS was
originally developed for use on
its iPhone devices. Now, the
mobile operating system is
referred to as iOS and is
supported on a number of Apple
devices including the iPhone,
iPad, iPad 2 and iPod Touch.
? BlackBerry OS (Research In
Motion): The BlackBerry OS is
a proprietary mobile operating
system developed by Research
In Motion for use on the
company’s
popular BlackBerry handheld
devices.
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15. OPERATING SYSTEMS FOR MOBILE DEVICES
? Symbian OS (Nokia): Symbian
is a mobile operating system
(OS) targeted at mobile phones
that offers a high-level of
integration with communication
and personal information
management (PIM) functionality.
? Windows Mobile (Windows
Phone 7): Windows Mobile is
Microsoft's mobile operating
system used in smart phones and
mobile devices – with or without
touch screens. The Mobile OS is
based on the Windows CE 5.2
kernel. In 2010 Microsoft
announced a new smart phone
platform called Windows Phone
7.
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16. TYPES OF APPLICATION SOFTWARE
? An Application Suite:
• Consists of multiple applications
bundled together.
• They usually have related functions,
features and user interfaces, and may
be able to interact with each other.
• Microsoft
Office, LibreOffice and iWork.
? Enterprise Software:
⚫ Addresses the needs of an entire
organization's processes.
⚫ Examples include enterprise resource
planning systems, customer
relationship management (CRM)
systems and supply chain management
software.
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17. TYPES OF APPLICATION SOFTWARE
? Enterprise Infrastructure
Software:
⚫ Provides common capabilities
needed to support
enterprise software systems.
⚫ Examples include databases, email
servers, and systems for managing
networks and security.
? Information Worker Software:
⚫ Lets users create and manage
information, often for individual
projects within a department, in
contrast to enterprise management.
⚫ Examples include time
management, resource management.
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18. TYPES OF APPLICATION SOFTWARE
? Content Access Software:
⚫ Is used primarily to access content
without editing, but may include software
that allows for content editing.
⚫ Examples include media players, web
browsers, and help browsers.
? Educational Software:
⚫ Is related to content access software, but
has the content and/or features adapted
for use in by educators or students.
⚫ For example, it may deliver evaluations
(tests).
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19. TYPES OF APPLICATION SOFTWARE
? Simulation Software:
⚫ Simulates physical or abstract
systems for research, training
or entertainment purposes.
? Media Development
Software:
⚫ Generates print and electronic
media for others to consume,
most often in a commercial or
educational setting.
⚫ This includes graphic-art
software, desktop publishing
software, multimedia
development software and
many others.
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20. TYPES OF APPLICATION SOFTWARE
? Product Engineering Software:
⚫ Is used in developing hardware and
software products.
⚫ This includes computer-aided
design (CAD), computer-aided
engineering (CAE), computer language
editing and compiling tools, integrated
development environments, and
application programmer interfaces.
? Entertainment Software:
⚫ Can refer to video games, screen savers,
programs to display motion pictures or
play recorded music, and other forms of
entertainment which can be
experienced through use of a computing
device.
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21. HOW DO I IMPROVE THE SECURITY OF
MY HOME COMPUTER?
? Connect to a Secure Network
? Enable and Configure a Firewall
? Install and Use Antivirus and Antispyware Software
? Remove Unnecessary Software
? Modify Unnecessary Default Features
? Operate Under the Principle of Least Privilege
? Secure Your Web Browser
? Apply Software Updates and Enable Future
Automatic Updates
? Use Good Security Practices
⚫ Use caution with email attachments and untrusted links
⚫ Use caution when providing sensitive information.
⚫ Create strong passwords.
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22. WEB APPLICATION & BROWSERS
? Web Application:
⚫ A web application or web app is any software that
runs in a web browser.
⚫ It is created in a browser-supported programming
language (such as the combination of JavaScript,
HTML and CSS) and relies on a web browser to
render the application.
? Web Browsers:
⚫ These programs allow users to navigate the Internet.
⚫ Some of the more common ones include Microsoft
Internet Explorer, Netscape Navigator, Mozilla
Firefox and Apple Safari 22
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23. WHAT IS VIRUSES?
? Viruses:
⚫ A computer virus is a program
designed to harm or cause
harm on an infected computer.
⚫ Its spreads through e-mail
attachments, portable devices,
websites containing malicious
scripts and file downloads.
⚫ A computer virus attaches
itself to the host files and
always activate whenever you
open the infected files.
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24. A VIRUS CAN RUN AS AN APPLICATION,
THEREFORE IT CAN -
? Remotely access a computer, giving anyone
complete control of the machine.
? Run as a background process, using internet
connection to send private data anywhere,
anytime.
? Delete files, run programs, edit registry and steal
information.
? Corrupt Windows files to make a machine
become unusable, causing it to crash and turn off
at any time.
? Key log information such as passwords,
usernames and credit card details.
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25. DIFFERENT TYPES OF VIRUSES
? Memory Resident Viruses: They
usually fix themselves inside the
computer memory. They get activated
every time the OS runs and end up
infecting other opened files. They hide
in RAM. For example CMJ, Jerusalem
Virus, Onehalf virus, Magistr, Junkie,
Satanbug etc.
? Overwrite Viruses: These types of
viruses delete any information in a
file they infect, leaving them partially
or completely useless once they are
infected. For example: Trj.Reboot
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26. DIFFERENT TYPES OF VIRUSES
? Web Scripting Virus: A web
scripting virus is a type computer
security vulnerability through websites
that breaches your web browser
security. This allowed the attackers to
inject client-side scripting into the web
page. It can bypass access controls, steal
your information from your web
browser. For example: JS.Fortnight
? Worm: This program is very similar to a
virus and has the ability to self-replicate
leading to negative effects on your
computer. For example: lovgate.F
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27. DIFFERENT TYPES OF VIRUSES
? Trojans: Trojans can illegally
trace important login details of
users online. For example E-
Banking is very common among
users, therefore, vulnerability of
tracing your login details
whenever your PC is working
without any strong powerful
antivirus installed.
? Email Virus: This is a virus
spread via an email. Such a virus
will hide in an email and when
the recipient opens the mail. 27
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28. DIFFERENT TYPES OF VIRUSES
? Browser Hijacker: This virus
can spread in many different
ways including a voluntary
download. If infects certain
browser functions especially in
form of re-directing the user
automatically to certain sites. A
good example is the cool web
search.
? Boot Infectors: They include the
boot sector plus master boot
record types. All the viral codes
can be separate location; however
they infect the hard disks or the
floppy. For example: the brain
virus.
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29. SOURCES OF VIRUSES
? Common source of infection is by visiting a
website. For example, many password trading
websites and WAREZ sites contain viruses. By
simply visiting the site with a vulnerable
browser, you may be infected by a virus.
? Another source of infection is by inserting flash
drives, or other portable media into an infected
machine, and then into an uninfected machine.
Viruses are often designed to transfer themselves
to portable media in an effort to physically
transport themselves to new environments. 29
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30. SAFEGUARDING AGAINST VIRUSES
? Antivirus software is used to prevent,
detect, and remove malware, including
computer viruses, worms, and Trojan
horses. A variety of strategies are typically
employed by Antivirus software. Signature-
based detection involves searching for
known patterns of data within executable
code.
? Some examples of Popular Antivirus:
⚫ Norton Antivirus (Symantec)
⚫ McAfee Antivirus
⚫ Bit defender
⚫ Trend Micro
⚫ AVG
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31. LIST THE SYMPTOM OF AN INFECTED
COMPUTER.
? The computer fails to start.
? Programs will not launch or they fail when
simple commands are performed.
? Filenames change or become unreadable.
? File contents change or are no longer accessible.
? Unusual words or graphics appear on the screen.
? Hard drives or disks are formatted.
? Variations occur in computer performance, such
as slowdowns in loading or operation.
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32. LIST THE STEPS FOR REMOVING A VIRUS
? Determine the type of virus
? Isolate all infected systems and disks
? Make sure you have a clean disk formatted as a
system disk
? Use the clean system disk to boot all systems
with suspected infection
? Scan every physical and logical hard disk, as well
as every disk
? Back up the necessary data and executable files
to trusted, clean media
? Clean the infected standalone workstations
? Clean the infected server
? Clean the disk 32
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33. EXERCISE – 3.1
1. What is Software? Explain with Example.
2. Define System Software with its classification and
example of them.
3. What is application software? What are the different types
of application software? Define them with example.
4. What are the main parts of operating system?
5. What is operating system? Define different types of
operating systems with example.
6. What are the functions of an OS?
7. Give some example of mobile base OS with their
proprietary.
8. How do you improve the Security of your Home
Computer?
9. What is Web Application & Web Browsers? Give two
examples of them.
10. What is virus? What type of harm it can do?
11. Write a short note on Antivirus.
12. Explain different types of viruses with example.
13. List the symptom of an infected computer.
14. List the steps for removing a virus.
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