"There are seven layers to the TCP/IP protocol architecture. The first is the physical layer, consisting of the cables, switches, and other network hardware. The second layer is the data link which connects the physical to the protocol layers. The third layer is the network and internet layer, which transports the information outside of the intranet. The fourth layer is called the transport layer and defines the protocol used to move the data across a network. The final three layers, five, six, and seven, are the application, session, and presentation layers. This is where the logic and protocols reside, which ensures the information can flow across the network, interact with the applications, and be presented to the users in a manner that makes sense."