Information
The login window prompts a user for his/her credentials, verifies their authorization level and then allows or denies the user access to the system.
Rationale:
Prompting the user to enter both their username and password makes it twice as hard for unauthorized users to gain access to the system since they must discover two attributes.
Solution
Perform the following to implement the prescribed state:
Open System Preferences
Select Users and Groups
Select Login Options
Select Name and Password
Alternatively:
Run the following command in Terminal:
sudo defaults write /Library/Preferences/com.apple.loginwindow SHOWFULLNAME -bool yes