Sound Card, also called audio card (called sound effect card in Hong Kong and Taiwan), is the most basic component of computer multimedia system. It is a kind of hardware that realizes the mutual conversion of sound waves/digital signals.

The basic function of a sound card is to convert original sound signals from microphones, tapes, and compact discs, and output them to sound equipment such as headphones, speakers, amplifiers, and tape recorders, or to emit the sounds of synthetic instruments through the Music Equipment Digital Interface (MIDI)