Internet protocol defines the rules and conventions for how devices can communicate over a network. It establishes the format for exchanging data so that devices using the same protocol can understand each other. The main purposes of IP are to define the basic unit of data transfer, perform routing functions, and establish rules for unreliable packet delivery and error handling. IP supports unicast, broadcast, and multicast services. IP addresses uniquely identify devices and allow for communication via the Internet Protocol. IPv4 uses four sets of numbers separated by dots, while IPv6 uses eight sets of hexadecimal digits separated by colons.

2. What is internet protocol?
 Rules and conventions explaining how something
must be done
 Used to describe how devices can communicate
 Protocol also defines the format of Data i.e. : being
exchanged.
 If we both utilize the same protocol then you know
how to format data so I will understand it and I know
how to format data so you will understand it

3. Purpose of the IP
 The Internet Protocol defines the basic unit of
data transfer (IP Datagram)
 IP software performs the routing function
 IP includes a set of rules that process the idea
of unreliable packet delivery.
 How hosts and routers should process packets
 How & when error messages should be generated
The Conditions under which packets can be
 discarded.

4. IP Service
IP supports the following services
 One-to-one (unicast)
 One-to-all (broadcast)
 One-to-several (multicast)

5. IP Address
 An IP address, or simply an "IP," is a unique address
that identifies a device on the Internet or a local
network. It allows a system to be recognized by other
systems connected via the Internet protocol. There are
two primary types of IP address formats used today —
IPv4 and IPv6.

6. IPv4
 An IPv4 address consist of four sets of numbers from 0
to 255, separated by three dots. For example, the IP
address of TechTerms.com is 67.43.14.98. This number
is used to identify the TechTerms website on the
Internet. When you visit http://techterms.com in
your web browser, the DNSsystem automatically
translates the domain name "techterms.com" to the IP
address "67.43.14.98."

7. IPv6
 The IPv6 address format is much different than the
IPv4 format. It contains eight sets of
four hexadecimal digits and uses colons to separate
each block. An example of an IPv6 address is:
2602:0445:0000:0000:a93e:5ca7:81e2:5f9d. There are
3.4 x 1038 or 340 undecillion) possible IPv6 addresses

8. Need of Internet
 Scientists and military experts were especially
concerned about what might happen in the event of a
Soviet attack on the nation’s telephone system. Just
one missile, they feared, could destroy the whole
network of lines and wires that made efficient long-
distance communication possible. In 1962, a scientist
from M.I.T. and ARPA named J.C.R. Licklider proposed
a solution to this problem: a “galactic network” of
computers that could talk to one another. Such a
network would enable government leaders to
communicate even if the Soviets destroyed the
telephone system.

9. Birth of ARPANET
 In 1965, another M.I.T. scientist developed a way of
sending information from one computer to another
that he called “packet switching.” Packet switching
breaks data down into blocks, or packets, before
sending it to its destination. That way, each packet can
take its own route from place to place. Without packet
switching, the government’s computer network—now
known as the ARPAnet—would have been just as
vulnerable to enemy attacks as the phone system.

10. “LOGIN”
 In 1969, ARPAnet delivered its first message: a “node-
to-node” communication from one computer to
another. (The first computer was located in a research
lab at UCLA and the second was at Stanford; each one
was the size of a small house.) The message—
“LOGIN”—was short and simple, but it crashed the
fledgling ARPA network anyway: The Stanford
computer only received the note’s first two letters.

11. BIRTH OF INTERNET PROTOCOLS
 By the end of 1969, just four computers were connected to the
ARPAnet, but the network grew steadily during the 1970s. In 1971, it
added the University of Hawaii’s ALOHAnet, and two years later it
added networks at London’s University College and the Royal Radar
Establishment in Norway. As packet-switched computer networks
multiplied, however, it became more difficult for them to integrate into
a single worldwide “Internet.”
By the end of the 1970s, a computer scientist named Vinton Cerf
had begun to solve this problem by developing a way for all of the
computers on all of the world’s mini-networks to communicate with
one another. He called his invention “Transmission Control Protocol,”
or TCP. (Later, he added an additional protocol, known as “Internet
Protocol.” The acronym we use to refer to these today is TCP/IP.) One
writer describes Cerf’s protocol as “the ‘handshake’ that introduces
distant and different computers to each other in a virtual space.”