Tracks are narrow bands organized as concentric circles much like the grooves on an LP record. A cylinder is comprised of all tracks on a disk that have the same number (consider two surfaces each on multiple platters in a hard disk drive). Besides these two organizations, a disk is broken into sectors which are pie shaped wedges comprised of multiple tracks. Sectors are often known as track sectors and store up to 512 bytes of data. Finally, a cluster consists of two to eight sectors and is the smallest amount of space that is used to store data on a disk. A cluster can store data from only one file. An individual file make consume multiple clusters In addition to these organizations, a FAT is created which acts as an index of the contents of the disk. It stores the names of each file on the disk, the size of each file, the starting cluster of the file and additional information including when each file was last changed. The FAT also indexes empty clusters available for storage.