There are lots of reasons to use the Guest User feature on your Mac. For most of us that'll be so others don't have unauthorized access to our files and settings. You can limit what they can and can't do fairly easily so you can be sure at all times that no one is doing things on your Mac that they shouldn't. Here's how to turn on the Guest User account:
- In the top menu bar, click on the logo and then System Preferences.
- Now click on Users & Groups.
- If you have an admin password set up (which you definitely should have), click on the lock in the lower left hand corner of the System Preferences panel and enter your password in order to make changes.
- Now click on Guest User in the left hand accounts pane.
- Check the box for Allow guest to log in to the computer.
- You can also enable parental controls and choose whether or not guests can connect to shared folders on your Mac.
That's it. If you have FileVault enabled, Guest Users will only be able to access Safari and nothing else in Login only mode. You can, of course, tweak settings to your liking.