The internet protocol can be abbreviated as IP. It is the host to host network layer delivery protocol for the internet. IP is an unreliable and connectionless datagram protocol that is a best-effort delivery service. The term best-effort means that internet protocol or IP provides no error control or flow control. Internet protocol uses only an error detection mechanism and discards the packet if it has been corrupted. The IP does its best to deliver the packet to its desired destination, but with no guarantees. If reliability is important, this IP must be paired with some reliable protocol such as TCP (works at the transport layer).

Internet protocol is also a connectionless protocol for the packet switching networks that uses the datagram approach. This tells us that each datagram is handled independently, and each datagram can follow a different route to the destination. This implies that datagrams sent by the same source to same destination could arrive out of order. In some cases some of them could be lost, damaged or corrupted during this transition. Again, IP relies on a higher level protocol to take care of all these problems. Packets in the IP layer are known as the datagrams.