Learn how passwords are used on a Mac
macOS is designed to give you a safe and secure computing environment. The security of your Mac depends a great deal on using secure passwords in key areas.
A login password, also called a user password, allows the user to log in and access the information on the Mac. Privileges are limited by the type of user. An administrator user is required to perform many important tasks, such as setting certain system preferences, installing software, and administering standard users. For more information, see Set up users, guests, and groups.
Passwords in iCloud Keychain