InformationThe automatic login feature saves a user's system access credentials and bypasses the login screen, instead the system automatically loads to the user's desktop screen.
Disabling automatic login decreases the likelihood of an unauthorized person gaining access to a system.
If Automatic login is not disabled an unauthorized user could login without supplying a user password or credential.
SolutionPerform the following to set automatic login to off:
Open System Preferences
Select Users & Groups
Click the lock to authenticate
Select Login Options
Select Automatic login and set it to Off
Run the following command to disable automatic login:
$ sudo defaults delete /Library/Preferences/com.apple.loginwindow autoLoginUser