Sound cards today generally plug into your Peripheral Component Interconnect (PCI) slot. Most sound cards are from one vendor producing a desired chipset. Then manufacturers take that chipset and add many different functions to make their product unique. Sound card only do four major things. They first play recorded music and sound files, games, and DVDs. Secondly they record audio from external sources like a microphone. Thirdly they synthesize sounds. Lastly the process existing sounds.
Most sound cards include the following:
-a digital signal processor (DSP) that computes most of the digital data.
-a digital to analog converter (DAC) for any of the audio going to speakers.
-an analog-to-digital converter (ADC) for audio coming through microphones.
-read-only memory (ROM) or Flash memory for storing data
-musical instrument digital interface (MIDI) for connecting to outside music
-jacks for connecting speakers and microphones, and ports for joysticks or game controllers.