Computer Science

Evolution of Computer Networks Class 12 CBSE (083): ARPANET, NSFNET and Internet

Class 12 · Computer Science

Evolution of Computer Networks (CBSE Class 12 Computer Science - 083)

A computer network is a collection of two or more computers and other devices connected together to share data, hardware, software, and internet resources. Today, computer networks are used in homes, schools, businesses, banks, hospitals, and governments for efficient communication and resource sharing.

Learning Objectives

Understand the concept of computer networks.
Learn the need and advantages of networking.
Study the evolution of computer networks.
Understand the role of ARPANET, NSFNET, and the Internet.

What is a Computer Network?

A Computer Network is a group of interconnected computers and other devices that communicate with each other to exchange information and share resources.

Definition: A computer network is a collection of interconnected computers that communicate and share data and resources using communication media and networking protocols.

Need for Computer Networks

Computer networks are used for the following purposes:

Sharing files and documents.
Sharing printers, scanners, and storage devices.
Communication through email, messaging, and video conferencing.
Accessing the Internet.
Online education and e-learning.
Online banking and e-commerce.
Remote access to computers.
Centralized data management.

Advantages of Computer Networks

Fast communication.
Easy sharing of hardware and software resources.
Reduced operational cost.
Improved collaboration.
Centralized data storage.
Efficient backup and security management.
Access to information from anywhere.

Evolution of Computer Networks

Modern computer networks have evolved over several decades. The journey began with ARPANET, expanded through NSFNET, and ultimately led to today's Internet.

Timeline of Network Evolution

Year	Network	Significance
1969	ARPANET	World's first operational packet-switching network.
1986	NSFNET	High-speed academic and research network.
1990 onwards	Internet	Global network connecting millions of devices.

ARPANET (Advanced Research Projects Agency Network)

ARPANET was the world's first computer network based on packet switching. It was developed by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense.

Key Features of ARPANET

Launched in 1969.
Developed by the U.S. Department of Defense.
Connected universities and research institutions.
Introduced packet-switching technology.
Allowed reliable communication between distant computers.
Laid the foundation for the modern Internet.

Did You Know? The first ARPANET connection was established between the University of California, Los Angeles (UCLA) and the Stanford Research Institute (SRI).

Packet Switching

Packet switching is a method of transmitting data in which a message is divided into smaller units called packets. Each packet travels independently through the network and is reassembled at the destination.

Advantages of Packet Switching

Efficient use of network bandwidth.
Reliable communication.
Supports multiple users simultaneously.
Reduces transmission delays.

NSFNET (National Science Foundation Network)

NSFNET was developed by the National Science Foundation (NSF) in the United States to provide a high-speed network connecting universities, research centers, and educational institutions.

Key Features of NSFNET

Started in 1986.
Connected educational and research institutions.
Provided faster communication than ARPANET.
Expanded networking across the United States.
Served as the backbone of the early Internet.
Helped connect regional and international networks.

The Internet

The Internet is a worldwide network of interconnected computer networks that enables billions of devices to communicate and share information using standard communication protocols such as TCP/IP.

Features of the Internet

Largest computer network in the world.
Connects millions of computers and smart devices.
Uses the TCP/IP protocol suite.
Supports communication, education, business, entertainment, and research.
Accessible 24×7 from almost anywhere in the world.

Services Provided by the Internet

Web Browsing (WWW)
Email
Video Conferencing
Online Banking
E-Commerce
Cloud Computing
Online Education
Social Networking
File Transfer
Online Gaming

Evolution Summary

Network	Developed By	Purpose	Importance
ARPANET	ARPA (USA)	Research and defense communication.	First packet-switching network.
NSFNET	National Science Foundation	Academic and research networking.	Backbone of the early Internet.
Internet	Global collaboration	Worldwide communication.	Largest global computer network.

Applications of Computer Networks

Online education
Digital libraries
Banking services
Healthcare systems
Government services
Business communication
Cloud computing
Video streaming
Online shopping
Social media platforms

Common Programming and Theory Mistakes

Confusing ARPANET with the Internet.
Assuming ARPANET and NSFNET are still operational as separate public networks.
Thinking the Internet is owned by a single organization.
Confusing the Internet with the World Wide Web (WWW).

Exam Tips

Remember the chronological order: ARPANET → NSFNET → Internet.
ARPANET was launched in 1969.
NSFNET was introduced in 1986.
ARPANET introduced packet switching.
NSFNET became the backbone of the early Internet.
The Internet is a network of networks that uses TCP/IP.

Frequently Asked Questions (FAQs)

1. What is a computer network?

A computer network is a group of interconnected computers that communicate and share resources.

2. What was ARPANET?

ARPANET was the world's first operational packet-switching computer network developed by the U.S. Department of Defense in 1969.

3. What was NSFNET?

NSFNET was a high-speed academic and research network launched in 1986 by the National Science Foundation and served as the backbone of the early Internet.

4. What is the Internet?

The Internet is a global network of interconnected computer networks that enables communication and information sharing worldwide.

5. What is packet switching?

Packet switching is a method of transmitting data by dividing it into smaller packets that travel independently through the network and are reassembled at the destination.

Summary

A computer network connects multiple computers for communication and resource sharing.
Networking improves collaboration, resource utilization, and access to information.
ARPANET (1969) was the first packet-switching network.
NSFNET (1986) connected universities and became the backbone of the early Internet.
The Internet evolved from these earlier networks into the world's largest network of interconnected computers.
Today, the Internet supports communication, education, commerce, entertainment, and countless online services.