Access Network Utility tools from Recovery.

Erase and reset a Mac to factory default settings (this is a multi-step process involving erasing the disk then installing system software.

Repair and erase hard disks with Disk Utility.

Fix a broken EFI partition (this is achieved through reinstalling system software).

Restore deleted system files (this is basically achieved through reinstalling MacOS system software on the Mac).

Reinstall current MacOS system software, including Mojave, High Sierra and Sierra, OS X El Capitan, Yosemite, Mavericks, and prior.

Disable System Integrity Protection, or enable SIP if it was disabled previously or never enabled in the first place for some reason.

Restore a Mac from a Time Machine backup.

There are a variety of troubleshooting steps and configuration options available once you’re booted into Recovery on a Mac, some of the included options are possibilities are as follows: Mac Recovery Options, Tasks, & Troubleshooting Tricks Instead, you are provided with a limited set of options and choices specific to recovery mode. When a Mac is booted into Recovery, the normal desktop and app experience is not available.

You will know the Mac is in Recovery Mode when the “Utilities” screen appears with various troubleshooting, recovery, and restoration features available.

Continue to hold Command + R keys for a few seconds until a moment after you see the  Apple logo, you can then release the keys and the Mac will boot into Recovery Mode.

As soon as the Mac starts booting up, hold down Command + R keys together.

Shut down the Mac, or reboot the computer.

Recovery Mode is accessed during system start by using a keyboard combination, here’s how it works: Always back up a Mac before performing any Recovery functions. If you are not sure what you’re doing, it’s best to not boot into Recovery on a Mac because you could potentially erase a Mac or perform an action you’d later regret, thus this is best for advanced Mac users with a thorough knowledge of what they’re doing and why. Typically Recovery Mode on a Mac is for advanced users and specific tasks like those outlined above only, and without a particular reason to do so there isn’t any practical purpose for booting into Recovery on a Mac unless you’re just curious. This article will explain how to start a Mac in Recovery mode, and detail the options available once a Mac is booted into Recovery.

Mac os x utilities on startup