A Sun Ray session is a group of services controlled by a Session Manager and associated with a user through an authentication token. The sessions reside on a server rather than on the desktop. Because Sun Ray Clients are stateless, a session can be directed or redirected to any Sun Ray Client on the appropriate network or subnetwork when a user logs in or inserts a smart card.

Hotdesking, or session mobility, is the ability for a user to remove a smart card, insert it into any other client within a failover group, and have the user's session "follow" the user, thus allowing the user to have instantaneous access to the user's windowing environment and current applications from multiple clients. Every Sun Ray Client is equipped with a smart card reader, and hotdesking is configured and enabled by default.

Sun Ray Software also provides Non-Smart Card Mobility (NSCM), or hotdesking without smart cards.