I have been reading about the OSI model and understand all the other layers but this layer seems to have many websites describing it differently
Are the sessions to keep track on connections, such as computer connecting to stream 1,stream 2 and stream 3. These would all have different sessions and be identified by their port.
Or are the sessions for the services being connected to such as session ids for websites.
Best Answer
First, let's have a look at the ISO/OSI stack vs the TCP/IP stack:
ISO/OSI layer 5 is not much "used" alone: it is implemented together with layers 6 and 7 to the TCP/IP Application layer, where network applications such as HTTP, NTP, IMAP etc. take place. In practice, its functions are mixed with the upper layers.
From Wikipedia: