However, groupware widgets differ from normal widgets. Session managers are often presented through metaphors. A spatial metaphor means that people can navigate a space, see who is around in it, and initiate conversation with people they meet. A rooms metaphor extends the spatial metaphor by providing rooms containing persistent groupware applications. As people enter a virtual room, all connections between people and between their groupware applications are automatically made.
Concurrency control is required to guard against inconsistencies, and to handle conflicting actions.
However, concurrency control in groupware must be handled differently than traditional concurrency control methods, simply because the user is an active part of the process. For example, people doing highly interactive activities will not tolerate delays introduced by conservative locking and serialization schemes. Finally, people can manage certain types of conflicting actions by social rather than technical means, implying that some indication of conflicts must be shown within the interface. Access control determines who can access a groupware object and when. Access control may be required when people wish to have their own private objects, where only they can manipulate or view them.