You have more than one Gmail account? Someone need to use your computer and sign in their account but you don't want to sign out your account?... You can sign in more than one account to switch between accounts without having to sign out and back in again, just follow the tutorial in gmail login multiple accounts
Notes: When you sign in multiple accounts, there will be one of them will be mark as the main account and whenever you sign in mail.google.com, your Inbox will direct to the main account inbox. To switch other account, click your avatar photo in the top right of the tab, choose the account you want to change. Sometimes, Gmail may ask you to re-type the password of the account you change.
