SESSION LAYER
Definition:
           
The  session layer allows session establishment between processes running on  different stations. It provides: 
             
Session establishment,  maintenance and termination:
           
It allows two application processes on different  machines to establish, use and terminate a connection, called a session.
           
Session support:
           
 It performs the functions that allow these processes to communicate over the  network, performing security, name recognition, logging, and so on.