Internet Protocol

The Internet Protocol (IP) is the main communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and important establishes the Internet.
IP, as the primary protocol in the Internet layer of the Internet protocol suite, has the task of delivering packets from the source host to the destination host solely based on the IP addresses in the packet headers. For this purpose, IP defines packet structures that encapsulate the data to be delivered. It also defines addressing methods that are used to label the datagram with source and destination information.
Historically, IP was the connectionless datagram service in the original Transmission Control Program introduced by Vint Cerf and Bob Kahn in 1974; the other being the connection-oriented.  The Internet protocol suite is therefore often referred to as TCP/IP.