Unit-IV
Internet
Introduction to the Internet
The internet is a global system of interconnected computer networks that use the standard
Internet Protocol (IP) suite (TCP/IP) to link devices worldwide. It is a network of networks
that consists of millions of private, public, academic, business, and government networks,
which carry information and services such as electronic mail, online chat, file transfer, and the
World Wide Web (WWW).
Definition:
• The Internet is a vast global communication network that connects computers
worldwide, allowing for data exchange and information sharing over various types of
networks.
History of the Internet
The origin of the Internet dates back to the 1960s when the U.S. Department of Défense
developed ARPANET, the precursor to the modern internet, to create a communication
network that could survive nuclear attacks.
Key Milestones:
• 1969: ARPANET (Advanced Research Projects Agency Network) was launched by the
U.S. Department of Défense.
, • 1971: The first email program was created by Ray Tomlinson.
• 1983: TCP/IP protocols were adopted, forming the foundation for internet
communication.
• 1989: Tim Berners-Lee proposed the World Wide Web (WWW), which became the most
popular aspect of the Internet.
• 1991: The first website went live.
• 1993: The Mosaic browser popularized web browsing.
How the Internet Works
The Internet works by using a series of standardized communication protocols (TCP/IP) that
allow different computers and networks to communicate with each other. Each computer or
device on the internet has a unique IP (Internet Protocol) address.
Components of the Internet:
1. Clients and Servers: Clients (computers, smartphones) request data, and servers
(powerful computers) provide data.
2. Routers: These are network devices that direct data packets between networks.
3. Domain Name System (DNS): DNS translates domain names (e.g.,
www.example.com) into IP addresses.
4. Protocols: TCP (Transmission Control Protocol) ensures reliable data transmission, and
IP addresses route data to the correct destination.
5. Packets: Data is broken down into small packets, transmitted across the network, and
reassembled at the destination.
Key Concepts:
• IP Address: A unique address assigned to each device on the internet.
• DNS: Converts human-friendly domain names into machine-friendly IP addresses.
• TCP/IP: The core protocol that manages how data is transmitted over the internet.
Services and Applications of the Internet
The internet provides numerous services that have revolutionized the way we communicate,
access information, and conduct business.
Key Internet Services:
1. World Wide Web (WWW): A system of interlinked hypertext documents accessed via
web browsers.
2. Email: Electronic mail is the exchange of messages between people using electronic
devices.
Internet
Introduction to the Internet
The internet is a global system of interconnected computer networks that use the standard
Internet Protocol (IP) suite (TCP/IP) to link devices worldwide. It is a network of networks
that consists of millions of private, public, academic, business, and government networks,
which carry information and services such as electronic mail, online chat, file transfer, and the
World Wide Web (WWW).
Definition:
• The Internet is a vast global communication network that connects computers
worldwide, allowing for data exchange and information sharing over various types of
networks.
History of the Internet
The origin of the Internet dates back to the 1960s when the U.S. Department of Défense
developed ARPANET, the precursor to the modern internet, to create a communication
network that could survive nuclear attacks.
Key Milestones:
• 1969: ARPANET (Advanced Research Projects Agency Network) was launched by the
U.S. Department of Défense.
, • 1971: The first email program was created by Ray Tomlinson.
• 1983: TCP/IP protocols were adopted, forming the foundation for internet
communication.
• 1989: Tim Berners-Lee proposed the World Wide Web (WWW), which became the most
popular aspect of the Internet.
• 1991: The first website went live.
• 1993: The Mosaic browser popularized web browsing.
How the Internet Works
The Internet works by using a series of standardized communication protocols (TCP/IP) that
allow different computers and networks to communicate with each other. Each computer or
device on the internet has a unique IP (Internet Protocol) address.
Components of the Internet:
1. Clients and Servers: Clients (computers, smartphones) request data, and servers
(powerful computers) provide data.
2. Routers: These are network devices that direct data packets between networks.
3. Domain Name System (DNS): DNS translates domain names (e.g.,
www.example.com) into IP addresses.
4. Protocols: TCP (Transmission Control Protocol) ensures reliable data transmission, and
IP addresses route data to the correct destination.
5. Packets: Data is broken down into small packets, transmitted across the network, and
reassembled at the destination.
Key Concepts:
• IP Address: A unique address assigned to each device on the internet.
• DNS: Converts human-friendly domain names into machine-friendly IP addresses.
• TCP/IP: The core protocol that manages how data is transmitted over the internet.
Services and Applications of the Internet
The internet provides numerous services that have revolutionized the way we communicate,
access information, and conduct business.
Key Internet Services:
1. World Wide Web (WWW): A system of interlinked hypertext documents accessed via
web browsers.
2. Email: Electronic mail is the exchange of messages between people using electronic
devices.
