That part of a track or band on a magnetic drum, a magnetic disk, or a disk pack that can be accessed by the magnetic heads in the course of a predetermined angular displacement of the data medium.

• 磁鼓、磁盘或磁盘组上的一条磁道或一组磁道的某个部分,在数据媒体旋转到预定的角度时,磁头能在该部分存取数据。