Public or shared computer - Select this option when you access Outlook Web App on a public computer. For example, Internet kiosks in airports, coffee houses, and conferences may be categorized as public or shared computers. While UW computer labs are very secure, you may want to consider this option for use in computer labs in case you forget to log out of your session. The Public or shared computer option is the default option and provides a short default time-out option of 15 minutes of inactivity.
Private computer - Select this option when you are the only person who uses a computer. This option permits a much longer period of inactivity before automatically ending the session. Its internal default value is 24 hours. The Private computer option is intended to benefit Outlook Web App users who use personal computers in their office or in their home.
In Outlook Web App, interaction between the client application and the Exchange server is considered activity. For example, if a user opens, sends, or saves an item, switches folders or modules, or refreshes the view or the Web browser window, this is considered activity.
If a user enters text in OWA items, it is not considered activity. For example, if a user types in appointments, meeting requests, posts, contacts, tasks, or other items, this is not considered activity.