While the Mac can use a hard drive formatted for Windows, some features may be limited. So it's a good idea to format a new hard drive specifically for macOS.

A Mac computer with an available USB port. An external drive or flash drive that you want to format. It can be an external hard disk, SSD, flash drive or USB drive.

If you want to re-format an external hard drive (a drive you plug into your computer, instead of installing inside of your computer) or flash drive, it's extremely easy to do.

How to Format SSD on a MacBook. A Solid State Drive is primarily used on laptops and other lightweight devices, as its compact size proves adequate for such portable hardware units.

External enclosures for 2.5-inch SSDs One of the easiest ways to seamlessly continue using your old 2.5-inch SSD is to install it in an external hard drive enclosure.