A hard disk may have hundreds or thousands of tracks. All the tracks with the same radius are known as a cylinder . Like tracks, cylinders are numbered beginning with zero. The number of platters and cylinders of a drive determine the drive's geometry . Most PCs require you to specify the geometry of a drive in the BIOS setup.
Most operating systems prefer to read or write only part of a track, rather than an entire track.
Consequently, tracks are divided into a series of sectors , each of which holds a fixed number of bytes, usually 512. To correctly access a sector, a program needs to know the geometry of the drive. LBA sequentially numbers sectors, letting programs read or write a specified sector without the burden of specifying a cylinder or head number. The first step in preparing your hard disk is viewing its partition information. Once you know how your hard disk is organized, you'll be able to determine how to reorganize it to accommodate Linux.