The session layer of the OSI Model is where sessions get managed. Being able to keep track of what data belongs to what process is a crucial part of being able to manage multiple sessions at the same time.
Authentication and Authorization occur in this layer as part of the session management process. This process allows us to separate what data gets accessed by whom. This process provides some Confidentiality in the CIA Triad.
It is the session layer where we see calls using RPC. Interprocess communication can also happen here. Another example of what the Session Layer’s usage is x.255. X.255 is a protocol used in managing sessions and will try to recover a session that gets dropped.