Launch a restricted guest session
Temporary session with restricted privileges
Once in a while a friend, family member, or colleague may want to borrow your computer. The Ubuntu Guest Session feature provides a convenient way, with a high level of security, to lend your computer to someone else. The feature is available to any regular user when logged in.
To launch a guest session, click your name in the menu bar and select Guest Session. This will lock the screen for your own session and start the guest session. A guest cannot view the home folders of other users, and by default any saved data or changed settings will be removed/reset at logout. It means that each session starts with a fresh environment, unaffected by what previous guests did.