If you have used Windows before, you might be aware of a handy feature you can do if you need to step away from your computer. You can “lock” the computer, which makes it inaccessible without entering the administrator password. Well, you can do the same thing (essentially) on a Mac, and here is how you do it.
1. Go into you Utilities folder (inside of your Applications folder) and click on “Keychain Access”
2. From there, click in the top-right where it says “Keychain Access”, then click on “Preferences”.
3. Check the box that says “Show Status in Menu Bar”
4. You will now have a little icon of a Lock in the menu bar.
5. Clicking it will make your screen go black. When you move the mouse, you are prompted to enter your password.
There you go!