Temporary users of your Mac. You can set an option in Users & Groups preferences to allow guest users to log in to your Mac, so you don’t need to add each guest as an individual user. You can use parental controls to set restrictions so guests can access only items that you want to share.
Guests don’t need a password to log in.
Guests can’t change user or computer settings.
Guests can’t log in remotely when remote login is turned on in Sharing preferences.
Files created by a guest are stored in a temporary folder, but this folder and its contents are deleted when the guest logs out.
Guest access works with the Find My Mac feature of iCloud to help you find your Mac if you lose it. You can locate your Mac if someone finds it, logs in as a guest, and then uses Safari to access the Internet.
Note: If FileVault is turned on, guests can only use Safari and can’t access your encrypted disk or create files.