The session manager system provides the client/server connections in NetWare. Sessions are part of a tree hierarchy where the Session Manager is the top-level session of the tree that ties all session providers together and is a session itself. Sessions are unique in relation to their parent and their domain name, which means two different sessions can have the same domain name, as long as their parents are different.
Sessions are used to set up a communication channel between two entities: The initiating entity, which creates a session, and the domain, which can be anything from a tree to a server to any other object. Sessions, therefore, form the established communication channel between two objects in a domain. Once the object has established a singular session, it can communicate with another object in the same domain. Domains can be hierarchical, with child domains narrowing the scope of their parents.