A User Session is a private area of memory used to hold that end-user's state data for the duration of their visit.
This session's data may consist of:
- Information loaded from a database.
- Data entered by an end-user.
- User credentials.
Each time a 
Form is served to an end-user, state information for that Form is added to that user's session. The session maintains the values of the 
Fields and 
Tables on the Form and these values persist while the session is active.
End-user-provided Field values are updated in their User Session when a Form is submitted, for example, when a button is clicked in the browser.
If an end-user has not interacted with your application for a period of time, their User Session will be discarded. The timeout period is 30 minutes by default and can be changed inside a Verj.io Runtime Environment's Administration Application.
Discarding an end-users User Session frees up memory for other end-users of your application, and so careful consideration should be given when deciding on a User Session timeout. The default 30 minute timeout strikes a good balance for most applications.
Interacting with a Form once their User Session has timed out will result in an error page being displayed.