Page 107 - Web Applications (803) Class 11
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BASICS OF NETWORKING AND 1
WEB ARCHITECTURE
As we know, social media websites and apps are the platforms that allow us to communicate with each
other through video call, message chat, voice call, etc. at any time and from anywhere. These websites
and apps provide such facilities to us with the help of a global computer network. A computer network is a
collection of interconnected computers that can communicate with each other through a communication
medium. A communication medium is a way through which data can be transferred from one computer to
another. It can be wired or wireless. The Internet is the world’s largest computer network.
In this unit, you will learn about the evolution of the Internet and its different terminologies. Next, you
will learn about different types of networks and protocols. Then, you will learn about different types of
network architecture. Further, you will learn about the web server and the web client. At the end of this
unit, you will learn about network threats and security measures.
1.1 THE INTERNET
The Internet is a worldwide network made up of numerous independently operated networks. It does
not have a centralised governing body. Internet Service Providers (ISPs) are a group of government and
private organizations that work together to provide Internet connectivity. The Internet allowed people to
share information and connect with each other over long distances. The maximum data transfer rate of a
network or Internet connection is referred to as bandwidth.
Evolution of Internet
Nowadays, we hardly think twice before logging onto the Internet and posting comments on Instagram or
Twitter. However, such instant communication was not possible many years ago. Smoke signals and pigeons
were used to send messages. Over the years, the need for instant and secure communication has led to
tremendous growth. The following diagram shows the evolution of the Internet:
During the Cold War, the
US Department of Defense
(DoD) recognized the need to
build fault-tolerant networks
that would not fail in the event The United States
It was in 1876 that of a nuclear attack and could Department of Defense saw
Alexander Graham Bell withstand a single point of the need to link different
proposed the idea of failure. Digital packet switching, TCP/IP (Transmission Control
communication via telephone which divides the message to geographic research Protocol/Internet Protocol)
lines. This led to the creation be conveyed into little portions computers to build a was created in 1970 for
of the Public Switched called packets, was proposed by network. As a result, in 1969, communication between
Telephone Network (PSTN) Paul Baran, Donald Davies, and the Advanced Research multiple heterogeneous
in 1877. It ushered in Len Kleinrock. Packet switching Projects Agency (ARPA) of networks. Along with many
new horizons by allowing the Pentagon created a smaller networks, the National
people to communicate via is based on link sharing, as computer network named Science Foundation (NSF) of
telephone lines. From that opposed to circuit switching, ARPANET. ARPANET made use the United States created
time, communication which reserves resources along of digital packet switching
was mainly through a dedicated communication technologies. NSFNET in 1984 for research
telephone lines. line. and teaching purposes.
Basics of Networking and Web Architecture 105

