When a user has multiple sessions open simultaneously, those sessions can interfere with each other (f.e. executing a search in one session will trigger search results in all sessions). Other commands or user-actions have a similar effect on all sessions.

Being able to have multiple sessions simultaneously which operate independent from each other, a user can execute time-consuming operations and still have the ability to do other tasks in PowerWeb; some actions are time-consuming no matter how performant the client is.