Bits and bytes
Audio is inherently an analog experience. Sound is created as compressed waves travel through the air and interact with our ear drums. Until recently, the techniques used to reproduce audio were also strictly audio as well. For example, a microphone records sound similarly to how our ears do by capturing changes in air pressure and converting them to electrical impulses. Speakers do the reverse by converting the electrical signals back into waves of air pressure.
Computers, on the other hand, are digital. Computers convert audio samples into bits and bytes by taking samples of the audio. To keep it simple, let's consider a system where the current frequency of the sound wave (that is, how fast the wave is moving) is captured as a 16 bit (2 byte) number. It turns out that a 16 bit number can capture numbers in a range from 0 to 65,536. Each sample of the sound wave must be encoded as a number in this range. Also, as we actually capture two samples each time (for stereo sound...