What happens next in this paragraph?

How to restore a macbook pro
Back up any files you want saved to an external hard drive or online cloud storage system.
Restoring your macbook pro will wipe and erase all the data from your computer's hard drive.
Power off your macbook and connect it to a power source.
This will prevent your computer from shutting down and interfering with the restoration process. Power on your macbook pro and wait for the apple startup sound.