Sector

A section of a computer disk, such as a hard drive disk or optical media such as CD ROM. These media are segmented into tracks, sectors and clusters, where a unique ID or address allows the drive system to store and later be able to retrieve data. This file address information is generally stored in sector number 0 on the disk in a file known as the FAT (File Allocation Table). The sectors as well as the rest of the organization of the diskette or disk are set up as a result of the process known as formatting.