If you want to utilize a drive with a Mac, here's how to format it.
- Disk Utility will be launched. Alternatively, go to Applications > Utilities or press Command + Space and type Disk Utility.
- On the left side of Disk Utility, you'll find a list of accessible drives. Select the drive you want to format. NOTE: Formatting your hard disc will wipe all of its contents, so create a backup beforehand!
- From the four options in the main window, select Erase.
- Disk Utility will determine the format for you automatically. This may be APFS, or it may be Mac OS Extended (Journaled) depending on how the drive is currently formatted and whether you using macOS High Sierra or an older version of the OS. If you'd like to use something else click on the Formatting options to reveal the drop-down window. Choose the format you require depending on how you intend to use the formatted drive
- After that, you'll need to give the drive a name. This may be whatever you like, as long as it's apparent and gives you an indication as to what's on the other side.
- Then, select Security Options from the drop-down menu. This will open a new window where you may select how you want the disc to be formatted, using a slider that ranges from Fastest to Most Secure. If you want to ensure that any files present on the disc are safely deleted, this is an important step to do.
- Fastest will wipe the disc clean by eliminating the header information, but the actual data will remain intact, although hidden. This implies you or someone else might quickly retrieve the information with data-recovery software, which isn't necessarily a good idea. Move the slider to the second option where it says 'This option writes a single pass of zeros over the entire disk.' This will overwrite the entire drive once.
- Continue pushing the slider to the right for more security. The following step will allow you to overwrite the drive three times. Moving it all the way to Most Secure will overwrite the drive seven times, but you'll have to wait a long time (depending on the size of the disc) before you can use it again.
- Wait while the contents of the disc are deleted and the drive is made ready by clicking Erase. A progress meter will show you how your hard disc is formatting and how long it will take to finish.
- Now you may copy your data to the freshly formatted hard disc.
