Your login password is not your Apple ID password
macOS asks for two different passwords at different moments, and confusing them costs a lot of failed attempts.
Published: · Source: Genius Manu
A Mac has two passwords that beginners routinely mix up.
The login password unlocks the Mac and belongs to the user account on this machine. macOS asks for it when you wake the Mac, install something, change a protected setting, or see a padlock in System Settings.
The Apple Account password belongs to your Apple ID and lives on Apple’s servers. It is for the App Store, iCloud, purchases and signing in on a new device.
They can be identical, which is exactly how the confusion starts — until you change one and the other keeps working. When a dialog asks, read the wording: if it names your account or says administrator, it wants the login password.
You change the login one in System Settings → Users & Groups, next to your account, and the Apple Account one in System Settings → your name → Sign-In & Security. The same panel is where you add a guest or a second user, which is worth doing if someone else uses the Mac occasionally.
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