Sound stored on a computer is digital .
Natural sound is the result of a stream of continuous changes of vibrations in the atmosphere.
The process of converting natural analog sound into discrete digital sound is digitization . Sampling Sampling involves the rate at which the converted sound is captured. The higher the sampling rate the higher the fidelity and the higher the storage requirements. Digital sound sampled at high fidelity rates requires massive storage. For example, the CD audio format can hold 600 million characters of text, but only 74 minutes of uncompressed music.