When your computer has been inactive for the set interval, the screen saver starts. Click Security, and then click Require password to wake this computer from sleep or screen saver.
Click Show All to go back to the main System Preferences window.Click Screen Saver, and then use the slider to choose 15 minutes (or less).From the Apple menu, choose System Preferences.See instructions below for how to set your screen to lock automatically for Mac or Windows devices: Mac How to Set Your Computer to Lock Your Screen Automatically This is necessary to prevent an unauthorized person from being able to see sensitive information or exploit access to your computer in your absence.
Unless your computer is in a secure space that is accessible ONLY BY YOU, you must run a screen saver that will automatically lock your screen after 15 minutes of inactivity and require a password to unlock it.
