The TCP/IP Reference Model is similar to the OSI Reference Model, but where the OSI Model is a generic to networking, the TCP/IP model is specific to TCP/IP. It is a concept explaining the makeup of TCP/IP. It is divided into layers to help understand it and design hardware or software for it.

The layers are:

• Application - Things like FTP, telnet, HTTP and SNMP clients. This is a combination of layers 7-5 in the OSI model.
• Transport - Reliable end-to-end communication. This is the same as layer 4 in the OSI model.
• Internet - Logical addressing (IP). Same as layer 3 in the OSI model.
• Network Access - Concered with physical connection of the network. Combination of layers 2 and 1 in the OSI model.