SOUND CARD

Sound Card

A sound card (also known as an audio card) is an internal computer expansion card  that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware inside the PC. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education and entertainment (games) and video projection.

Uses

The main function of a sound card is to play audio, usually music, with varying formats (monophonic, stereophonic, various multiple speaker setups) and degrees of control. The source may be a CD or DVD, a file, streamed audio, or any external source connected to a sound card input.
Audio may be recorded. Sometimes sound card hardware and drivers do not support recording a source that is being played. A card can be used, again in conjunction with free or commercial software, to analyse input waveforms.