Add a Guest User account to your Mac

As you probably know, you can add multiple users to your so that every person in your home or office, say, can have their own space to work and to set things up how they like them.
But there's another kind of account you can turn on: a Guest account.

Turn it on in System Preferences > Users and Groups, and now you'll be presented with Guest as an option at the login screen. Anyone can use it - no password needed - but once they're finished everything they do will be wiped.
This is great not just for in foyers or spare rooms, say, but it's also great for if a friend or colleague says, Can I just borrow your or a minute to do something?\n You probably should turn off Automatic login and set your Security and Privacy settings to require a password after, say, five seconds of sleep or screensaver time.
That way you can be sure nobody will be able to access your stuff, but when they try to use your hey'll be offered the option of switching user and can then pick Guest.