An expansion board that enables a computer to manipulate and output sounds. Sound cards have become commonplace on modern personal computers and are typically associated with the consumer market. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.

Some sound cards also support MIDI, surround sound and more. In addition, most PC sound cards are Sound Blaster- compatible, which means that they can process commands written for a Sound Blaster card, a standard in consumer PC sound.