This video is about how to lock the screen in Mac OS X.
1. Opening the Keychain Access utility: Open up the Utilities folder. You can get to this by either hitting Command+Shift+U with the desktop (Finder) selected, or by opening Finder, browsing to the Applications folder, then double clicking on the Utilities folder.
2. Opening the Keychain Access Preferences: Once you have Keychain Access opened up, you'Â€Â™ll see the Keychain Access window on your screen. You can ignore this, because what we really want to get into are the Keychain Access preferences. To reach these preferences, click on the words Keychain Access at the top left of your screen and then select Preferences from the drop-down menu.
3. Modify Keychain Access Preferences: All we need to do in this window is check the box labeled Show Status in Menu Bar. Once completed, go ahead and hit the red button (X) at the top left of this window to close it. You can also close the main Keychain Access window.
4. Lock Screen (if so desired).
You can now lock your screen by using the padlock icon at the top right of you screen, located on the menu bar to the left of the clock and other icons.