You may be the only person that uses your Mac and if so, you probably do not need to learn much about Users & Groups but if you share your Mac from time to time with friends or family, knowing how to set up Users and Groups can be handy.
When you open the User & Groups panel in System Preferences you can add or delete new users. When you do this you will be confronted with a pop-up box that will ask you to choose a user type. Here’s a run-down of the various types of user:
Administrator
An administrator user can add and manage other users, install apps, and change settings. The new user you create when you first set up your Mac is an administrator. Your Mac can have multiple administrators. You can create new ones, and convert standard users to administrators. Don’t set up automatic login for an administrator. If you do, someone could simply restart your Mac and gain access with administrator privileges. To keep your Mac secure, don’t share administrator names and passwords.
Standard User
Standard users are set up by an administrator. A standard user can install apps and change settings for his or her OWN use. Standard users can’t add other users or change other users’ settings.
Managed User
Users who are managed with parental controls can access only the apps and content specified by the administrator managing the user. The administrator can restrict the user’s contacts and website access, and place time limits on computer use.
Sharing Only User
Sharing-only users can access shared files remotely, but can’t log in to or change settings on the computer. To give the user permission to access your shared files or screen, you may need to change settings in the File Sharing, Screen Sharing, or Remote Management panes of Sharing preferences.
Group
A “group” allows multiple users to have the same access privileges. For example, you can grant a group specific access privileges for a folder or a file, and all members of the group have access. You can also assign a group specific access privileges for each of your shared folders.You control a group’s access to your shared folders by setting access permissions in the File Sharing section of Sharing preferences.
Guest User
Guest users can use your computer temporarily without you having to add them as individual users. You can set restrictions and guests can access only the items you want to share. Files created by a guest are stored in a temporary folder, but this folder and its contents are deleted when the guest logs out. The guest account works with the Find My Mac feature of iCloud, which can help you find your Mac if you lose it. You can locate your Mac if someone finds it, logs in as a guest, then uses Safari to access the Internet. Guests don’t need a password to log in, can’t change user or computer settings and can’t log in remotely when remote login is turned on in Sharing preferences. I use the guest user when giving a presentation in Keynote so that my email and Messages apps don’t constantly interrupt my presentation.