Sessions

See where you are signed in and sign out devices you do not use or do not recognize.

Open Personal settings and select Sessions.
Where you are signed in lists each browser and device, with its address, when it was last active and when it signed in. The one you are using is marked This browser.
Select Sign out next to a session, or Sign out all others to keep only this one.

Signing out a session signs it out of every app.