When the page is refreshed, the current state of the page is not kept intact. HTTP cookies could be used to maintain some state, but they are limited in size, and are transmitted back to the server with each request. Some client state information should also be restored when the user logs in on different machines.

As a user navigates within Windchill, they may make changes that affect the user interface display, such as selecting a tab on the information page (for example, selecting My Tab). If the browser is refreshed, the user may expect to remain on their last active tab. To retain this information, some sort of persistence mechanism is required to refresh the page to the correct state .

There are two persistence mechanisms available for use. The Client State Provider will store information in the browser and will be specific to that particular browser on that particular machine. The Server State Provider will store information in the database and will make the information available for that user on any browser and any machine.