Sample rate is the amount of time between audio samples determines the quality of the reproduction. This is called the sample rate, that is the rate at which each sample is recorded. The sample rate is usually described in terms of cycles per second (Hertz/Hz) or thousands of cycles per second (Kilohertz/kHz).
Compact Discs use a sample rate of 44.1 kHz, so it contains 44,100 samples for every second of digital audio. In fact, it is actually double that because CDs are in stereo so they must contain two channels of audio samples.