In a CD (and any other digital recording technology), the goal
is to create a recording with very high fidelity (very high
similarity between the original signal and the reproduced
signal) and perfect reproduction (the recording sounds the same
every single time you play it no matter how many times you play
it). To accomplish these two goals, digital recording converts
the analog wave into a stream of numbers and records the numbers
instead of the wave. The conversion is done by a device called
an analog-to-digital converter (ADC). To play back the music,
the stream of numbers is converted back to an analog wave by a
digital-to-analog converter (DAC). The analog wave produced by
the DAC is amplified and fed to the speakers to produce the
sound. The analog wave produced by the DAC will be the same
every time, as long as the numbers are not corrupted. The analog
wave produced by the DAC will also be very similar to the
original analog wave if the analog-to-digital converter sampled
at a high rate and produced a