If you just built a PC, or added a brand new hard drive or SSD to an existing computer, you have to format it before you can actually store data on it. This is called 'initializing' the drive.

You might need to format an external hard drive before you can use it with your computer. We have some tips to help the process go smoothly.

How to Format an OS X Terminal Hard Disk. Mac OS X Mountain Lion gives users several ways to access the Terminal and three common options for formatting a hard drive.