Transmission control Protocol (TCP) was developed before OSI model. Therefore, the layers in the TCP/IP protocol do not match exactly with those in the OSI model. The TCP/IP protocol is made of 5 layers: physical, data link, network, transport, and application. OSI has 7 layers.

Here follows the comparison:

Application layer of TCP/IP = Session, presentation, and application layers of the OSI model.

TCP & UDP protocol of TCP/IP = Transport layer of OSI model

(IGMP, ICMP, ARP, RARP)IP protocol of TCP/IP = Network layer of OSI model

At Data Link & Physical layers of OSI, TCP/IP does not define any specific protocol of its own. IP layer of TCP/IP is capable of interfacing with many available standards.  for example Ethernet, Token Ring, FDDI, HSSI, and ATM.