Web application security is the process of protecting websites and online services against different security threats that exploit vulnerabilities in an application’s code . Common targets for web application attacks are content management systems Web application security is important to any business as it helps to keep web applications functioning smoothly and protect businesses from cyber vandalism, data theft, unethical competition, and other negative consequences . Web applications may face a number of attack types depending on the attacker’s goals, the nature of the targeted organization’s work. A web application (web app) is an application program that is stored on a remote server and delivered over the internet through a browser interface. Web services are web apps by definition and many, although not all, websites contain web apps.

1. Unit 4B :- Web Applications and
Security

2. Session 1: Working With Accessibility
Options
 Computer Accessibility refers to the user friendliness of a computer system for all,
regardless of their disability,. It enables a person with a disability or impairment to use a
computer. It is known as Assistive Technology. There are numerous types of impairment
that impact computer usage. These include
1. Visual Impairment
2. Motor or dexterity impairment
3. Hearing disability
4. Cognitive disability
5. Speech Impairments
6. Illiteracy

3. Introduction
 Accessibility means providing
such services for people with
disabilities, so that they can
perform on complete their work
without facing problem. Some
Accessibitly options are available
in OS .
 Magnifier
 Narrator
 On screen keyboard
 Mouse easier to use

4. Session 2: Understand Networking Fundamentals
 Computer networking refers to interconnected
computing devices that can exchange data and
share resources with each other. These
networked devices use a system of rules, called
communications protocols, to transmit information
over physical or wireless technologies.
Computer Network

5. How Computer Network helps?
1) File Sharing
2) Collaboration and communication
3) Sharing computer peripherals
4) Data backup

6. Advantages
 Speed:- Sending and receiving files on a computer network is quick
and easy. You can open the drive of another computer to copy files
while working on your computer.
 Centralized Software Management:- There is no need to duplicate
data on all the computers. Data in one computer that acts as a server
is enough. The file server stores all the software.
 Resource Sharing:- Resources such as printers, scanners and
modems can be shared in network.
 Cost Efficient:- The cost of additional hardware for individual devices
is reduced.
 Security:- Important files are password. All the users do not have the
access to such files.

7. OSI
Model

8. Transmission
Media
Computers in a network can
be wired or wireless. The
various types of transmission
media include Twisted Pair
cable, coaxial cable, optical
fiber, radio link, satellite link
and infrared transmission.

9. Twisted Pair
Cable
 A twisted pair cable is
made up of two plastic
insulated copper wires
twisted together to form a
single media.
 Out of these two wires, only
one carries actual signal
and another is used to for
ground reference.

10. Optical fiber
An optical fiber is used for
communication. It enables the
digital data transmission over
longer distances.
It is used as a medium for
networking.

11. Coaxial Cable
Coaxial cable may be rigid or
flexible. The data transmission
characteristics of coaxial cable
are much better than those of
twisted pair cables.
These cable are used by
telephone companies.

12. Types of Network
Configurations / Architecture
 Network Configuration means the design of a computer
network. The two main types of network configurations are:
 Peer-to-peer Network
 Client-server Network

13. Peer-to-Peer Configuration
 In this network has equivalent
capabilities and responsibilities. These
computer are connected in a network
but do not have a server. The printer
can be connected to a computer which
is responsible to other computers.
 Examples:- Two or more people with
their computers are connected to share
files directly with one another.

14. Client -Server Configuration
 In this network, a single powerful
computer acts a server. It is
connected to multiple computers
called clients.
 The server stores all the files,
database and complex
applications. The server serves
its clients by answering and
providing results to the queries
by clients.
 Example:- Bank Account

15. Components of a Network

16. Hub
 A hub is central device
in a network that
provides connection
among the computers
or nodes. It is used in
star topology.

17.  A Switch which
connects multiple
communication lines
together. It is used to
create temporary
connections between
two or more devices
linked to each other .
Switch

18. Repeater
 A repeater is network
device that increases
the range of a
transmitted signal by
re-transmission.

19.  A router is a network
device which routes
the information
around the network.
It connects one
network one network
to another.
Router

20. Gateway
 A gateway acts as
a route ”gate”
between two
networks. It
connects two
different types of
network to share
information. Ex.
Gmail, yahoo.
Bridge
 A bridge is a networking device responsible
for filtering the data. It checks the
destination address of a packet and
decides whether it should be forwarded or
dropped.

21. Network Operating
System (NOS)
 The network required
some software to control
the information transfer
activity on the network,
like the traffic police
controls the traffic, the
software called the
NOS.
Network Interface
Card (Network Adapter)
 Network card is a necessary
component of a computer without
which a computer cannot be
connected over a network.
 Types of NIC
 1)Wired NIC
 2) Wireless NIC

22. Types of Computer Network

23. Types of Network
It can be classified on the basis of geographical spread.
Personal Area
Network
PAN
Local Area
Network
Metropolian
Area Network
WAN
Wide Area
Network
LAN MAN

24. Personal Area Network
 PAN is a computer network
organized around an individual.
 These devices are connected
through a wired or wireless
connection.
 Wireless PANs use Bluetooth or
sometimes infrared connections.
 Bluetooth PANs are called piconets.
 Examples :- Digital photos and
music.

25. Local Area Network
 A network in a confined area
such as an office, a building or a
college campus is called Local
Area Network.
 The basic purpose of LAN is to
share may be hardware
resources such as printer, hard
disk, software resources such as
data, information and programs.

26. Metropolitan Area Network (MAN)
 A Metropolitan Area Network is a
network spread over an entire city.
 It is larger than LAN.
 Example:- Cable Television,
branches of school , office and
bank in the same city.

27. Wide Area Network (WAN)
 The computers are spread
across the cities, countries or
continents.
 If facilities efficient or exchange
of information as at high speed.
 The Internet and ATMs are
example of WAN.

29. What Is Internet ?
 Internet is the collection of
interconnected computer
networks. It uses the Internet
Protocol (TCP/IP) to server
billons of users worldwide.
 It is a network of network that
consists of millions of private,
public, academic, business and
government networks.

30. Who Governs Internet ?
 Internet Activities Board: It is a volunteer organization that
provide architectural guidance activities to and resolves conflict for
the Internet Engineering Force Task.
 Internet Corporation for Assigned Names and Numbers: IP
addresses, Domain Names,
 World Wide Web Consortium W3C: It develops protocol and
guidelines that ensure the long-term-growth of the Web.

31. A Modem
Internet Application Software
An Internet Service Provider
A Web Browser
Telephone Lines
A Web Browser
Accessing the

32. Modem
 It is used for data transfer from
one computer to another
computer network through
telephone lines. The computer
network works in Digital mode
and Analog mode for carrying
message.
 Modulator converts information
from analog to digital mode at
transmitting end and
demodulator converts digital to
analog mode at receiving end.