Increasing hardware efficiency and an expanding array of digital audio representation formats are giving rise to a wide variety of new digital audio applications. This paper introduces digital audio signal compression – the removal of redundant or otherwise irrelevant information from a digital audio signal. We begin by defining some useful terminology, then present a typical “encoder” (as compression algorithms are often called) and explain how it functions. Finally, we consider some standards that employ digital audio signal compression and discuss the future of the field.