Platter

An aluminum, glass, or ceramic disk that is coated in a magnetic media and is located within a hard disk drive to permanently store all your computer's data. When the computer is turned on, these platters will begin to rotate at so many rotations per minute (RPM). This rate varies depending upon the model of hard drive you have; an example of how fast a hard drive may spin is 7200 RPM. As the disk platters are rotating, the read/write head accesses information on one of the platters. It is not uncommon for a computer hard disk drive to have multiple platters. To help store and retrieve the data from the platter, data is stored in tracks, sectors and cylinders on each platter.

Also see: Cylinders, Hard disk drive definitions, RPM, Sectors, Tracks