Sound is the continual vibration of air particles and is an analogue signal. Therefore, we need to convert sound into binary to be able to process and store it using a computer.
A sound card translates between the outside world's analogue information and a computer's digital information. It uses an analogue to digital convertor (ADC) to change sound into a digital format the computer can understand, and a digital to analogue convertor (DAC) to change digital information into sound that you can hear.
Digital sound is broken down into thousands of samples per second.
Sample frequency is the frequency at which a sample in a sound file is taken. Most music CDs have a sample frequency of 44,100 hertz (samples per second). Each sound sample is stored as binary data.
A computer's sound card contains: