The third layer of the OSI Reference Model. The OSI model has been designated by ITU and ISO to enable data communication between different computers, and it standardizes both the overall network structure as well as protocols used therein. Network Layer is used to both transmit and relay data among multiple networks. see OSI Reference Model
The layer of the OSI model that creates a communication path between two computers via routed packets. Transport protocols implment both the Network layer and the Transport layer of the OSI stack. IP is a Network layer service.
In the OSI model, the logical network entity that services the Transport Layer. It is responsible for ensuring that data passed to it from the Transport Layer is routed and delivered through the network.