Load balancing : Load balancing among local servers : Distributing new sessions among your servers : Sessions
Once a new session has been routed, FortiADC can route traffic from that same session to the same back-end server. This is in order to preserve a sense of continuity with the client.
Because FortiADC is between the client and the server, it divides that one session into two:
client-side session
server-side session
Each side can be configured separately.