Turn on (start up) your Mac
Press the power button 
.
- On Mac notebook computers, the power button is a key in the top corner of the keyboard, or a circular button next to the keyboard.
- On Mac desktop computers, the power button is a circular button on the front or back of the computer.
After you turn on your Mac, it begins the startup process. If it doesn't turn on, learn what to do.
Turn off (shut down) your Mac
- Choose Shut Down from the Apple menu.
- Or hold down the power button for up to 3 seconds, until your Mac asks whether you're sure that you want to shut down your computer now. Click Shut Down.
Just as your Mac follows a startup process after it turns on, it follows a shutdown process before it turns off. That process includes automatically quitting all open apps and logging out of your OS X user account.
If you can't shut down your Mac because it isn't responding, you can force it to turn off without shutting down. Hold down the power button for 5 seconds, until your Mac turns off. Use this method only when you can't shut down. You'll lose any unsaved changes to documents that you have open.
Learn more
- If your Mac is turned on, briefly pressing the power button wakes your Mac or puts it to sleep. This shortcut requires OS X Mavericks v10.9 or later and is equivalent to choosing Sleep from the Apple menu.
- If you use VoiceOver, be aware that there is no audible cue when your Mac goes to sleep.
- Learn keyboard shortcuts for sleep, log in, and shut down.