Sound Card, printed circuit board, or card, that can translate digital information into sound and back; also called a sound board or sound adapter. Sound cards plug into a slot on the motherboard (the main circuit board of a computer) and are usually connected to a pair of speakers . To play sounds, the sound card receives digital information from a stored file and turns it into an electrical signal it sends to the speakers, which produce the sound.

If the sound card is attached to a microphone, the sound card can take the incoming sound and convert it into digital information by sampling, or taking tiny sections of, the sound many times each second (the most sophisticated sound cards can take almost 200,000 samples per second, but most take around 50,000 to 100,000 samples per second). Each sample is given a number that represents the loudness and tone of the sample and the order in which it occurs in the entire sound.