Q. What is the working of Sound cards?

Multimedia has become a very significant part of today's PC. Home user wants hear songs and watch movies. The Software developer hacking away at her computer wants to have computer playing OGG(The latest Free Sound format standard) or MP3 in the background.  So the sound system is a very significant part of system.

As you must have read in your high school physics that sound is a longitudinal wave travelling in a medium generally air in the case of music. Sound can be encoded in electrical form employing electrical signals that encode sound strengths. This is known as analog audio. This analog audio is converted to digital audio that is conversion of those signals in bits and bytes by the process known as Sampling.  In Sampling analog 'samples' are taken at regular intervals and amplitude (Voltage) of these samples is encoded to bits. These sounds are manipulated by your PCs microprocessor etc. To play back these digital audio sounds, the data are sent to Sound card that converts them to analog audio that is played back through speakers.