CD disk is an optical disc, on which data is recorded as a set of dips in the surface.When a laser beam shines across the dips,the reflected distortion represents the data.

• CD盘是一种光盘，其数据以一组坑的形式记录在光盘表面上，当激光束扫过这些坑的时候，返回的失真程度就代表了这些数据。