Track (disk drive)
A disk drive track is a circular path on the surface of a disk or diskette on which information is magnetically recorded and from which recorded information is read.

A track is a physical division of data in a disk drive, as used in the Cylinder-Head-Record (CCHHRR) addressing mode of a CKD disk. The concept is concentric, through the physical platters
Hard disk platter
A hard-disk platter is a component of a hard-disk drive: it is the circular disk on which the magnetic data is stored. The rigid nature of the platters in a hard drive is what gives them their name . Hard drives typically have several platters which are mounted on the same spindle...

, being a data circle per each cylinder of the whole disk drive. In other words, the number of tracks on a single surface in the drive exactly equals the number of cylinders of the drive.

Tracks are subdivided into blocks (or sectors, pages) (see: Storage block
Storage block
A storage block is a physical sector on the surface of a disk or diskette. It is the smallest unit of transference between the main memory and a given disk drive....

 and Virtual page).

The term track is sometimes prefaced with the word logical (ie: "3390-9 has 3 logical tracks per physical track") to emphasize the fact when used as an abstract concept, not a track in the physical sense.
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