Audio/video signals represented by discrete variations (in voltage, frequency, amplitude, location, etc.). A digital clock, for example, displays the time as discrete numeric values rather than angular displacement of analog hands. In general, digital signals can be transmitted faster and more accurately than analog signals. As an example, music from digital cd's is usually more clear than music from analog records.
are a representation of physical signals using numbers, usually called "samples," to represent amplitude or intensity. The range of the numbers in a sample is the major determiner of the signal-to-noise ratio.