Definition and stuff:
A sound card (also referred to as an audio card) is a peripheral device that attaches to the ISA or PCI slot on a motherboard to enable the computer to input, process, and deliver sound.
The sound card's four main functions are: as a synthesizer (generating sounds), as a MIDI interface, analog-to-digital conversion (used, for example, in recording sound from a microphone), and digital-to-analog conversion (used, for example, to reproduce sound for a speaker). The three methods of sound synthesis are through frequency modulation (FM) technology, wavetable, and physical modeling.
Creative Lab's Sound Blaster is the de facto standard sound card, to the extent that some people use the name as a generic term. Most sound cards in the past have been Sound Blaster-compatible, because most programs that use the sound card have been designed that way. Sound cards were once all connected to the ISA slot. However, because connection to the PCI bus offers advantages such as improved signal-to-noise ratio and decreased demand on the CPU, sound cards being produced today are intended for use with a PCI bus.
