Internet Protocol
The Internet Protocol (IP) is a protocol used for communicating across a heterogeneous network. It is the protocol on which the Internet is built.
IP provides computers with communicable addresses that are globally unique.
In the seven-layer OSI model, IP is a network-layer protocol, sitting on top of the link layer. Data sent over IP is encapsulated into one or more packets. This provides a level of abstraction; applications and protocols using IP can be agnostic as to the actual networks traversed by each packet. Each such network can have its own method of addressing. The Address Resolution Protocol handles the transaction between IP addresses and link-layer network addresses.
IP is a connectionless protocol.
IP provides best-effort delivery for its data payload, making no guarantees with respect to reliability. Without notification to either the sender or receiver, packets may become corrupted, lost, reordered, or duplicated. This design reduces the complexity of Internet routers.