

It will also be incapable of storing certain types of information that are necessary to make your volume bootable or encrypted. While your Mac can read and write to such filesystems, it will not be as efficient as the native macOS Extended file system that macOS wants to use. Virtually any new hard drive will come pre-formatted, so you can plug it into your Mac and begin using it ‘out of the box.’ The problem is that it has probably been formatted with a Windows PC native filesystem.

This includes creating a file system on the drive so that data can be organized into files and folders. Formatting refers to the process by which the hard drive is prepared to store data. One of the first steps you must perform before using a new hard drive for backup purposes is to format it.
