Let occasional users log in as guests
Did you know that you can let other people use your Mac temporarily as guest users without adding them as individual users.
This is great because:-
- 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.
NOTE: Files created by a guest are stored in a temporary folder, but that folder and its contents are deleted when the guest logs out.
On your Mac, choose Apple menu 
> System Preferences, then click Users & Groups 
.If the lock at the bottom left is locked 
, click it to unlock the preference pane.
Select Guest User in the list of users.
Select “Allow guests to log in to this computer”.
If you like, select “Limit Adult Websites” to prevent the guest from accessing adult websites.
To let guests use your shared folders from another computer on the network, select “Allow guest users to connect to shared folders”.