Storage of files in pieces scattered on a disk. As files grow on a hard disk, they can be divided into several small pieces. By fragmenting files, the operating system makes reasonable use of the disk space available. The problem with file fragmentation is that the disk heads must move to different locations on the disk to read or write to a fragmented file. This process takes more time than reading the file as a single piece. To speed up file operations, you can use a disk optimizer or defragmenter.
See also FAT16; FAT32; defragmenter.