IP (Internet Protocol) is a network layer routable protocol of TCP/IP stack that unites the network segments into one network and ensures the delivery of data packets between any network nodes thru a random number of the intermediate nodes (routers).
The IP does not guarantee a reliable delivery of a packet to its addressee; in particular, the packets may arrive in a different order than the one in which they were sent, they may duplicate (two copies of the same packet may arrive), they may get damaged (normally, the damaged packets are destroyed) or they may never come. Some higher level protocols (e.g. TCP) that use the IP as transport provide the guaranteed error-free packet delivery.
