Disk formatting. When you format a disk you create tracks and sectors on which system and user data may be stored. A file when stored on the formatted disk has an entry in the File Allocation Table (FAT) that is used to record the clusters (a number of contiguous or non contiguous sectors) on which each file's data is stored. When a user sends a request to access a file, the FAT is referred to and the necessary clusters are read in proper order and the file is retrieved.