Definition: track

(1) A single song or musical composition on a CD or as a download. See online music store.

(2) The metal interconnecting pathways on a chip that tie the transistors, resistors and capacitors together. There can be eight or more layers of tracks on a chip (integrated circuit). See MOSFET.

(2) The storage channel on a disk or tape. On magnetic disks (hard, floppy, Zip, etc.), tracks are concentric circles. CD and DVD tracks have one continuous, spiral-shaped channel starting near the center and moving outward. On magnetic tapes, tracks are parallel lines along the length of the tape. Helical scan tapes use diagonal lines (see helical scan).

On magnetic devices, bits are recorded as reversals of polarity in the magnetic surface. On optical media, the bits are recorded either as physical pits under a clear, protective layer or as changes in the reflectivity of the material. See magnetic disk and optical disc.

Tracks and Sectors

On disk, tracks are concentric circles. On tape, they are generally parallel with the length, although helical scan tracks run diagonal.

Track Width

The width of a track is wider than the bit length. At the beginning of the 21st century, the state-of-the-art was more than 30,000 tracks per inch (tpi).