Example: "He used Apple Disk Utility to format his new hard drive for his Mac."
Formatting a disk involves rewriting the directory structure, or file system, of a disk. All disks must be formatted using a supported file system in order to work with a computer. Therefore, it may be necessary to format (or reformat) a disk if it is not formatted for the computer you are using. While the formatting process technically does not erase the files on the disk, it does make them inaccessible, since they are no longer part of the directory structure. Therefore, make sure you don't format or reformat a disk that contains important data.