D is for Digital

Digital, as opposed to analog. Discontinuous, versus continuous. Digital, as in a series of 1s and 0s, either on or off, black or white. It's not how we usually think about life, with our shades of grey, but by streaming these 1s and 0s we can build immensely detailed information streams - and information is what we and the world are all made of...

Of course an analog waveform can describe the same information. It's a little like quantum physics vs classical: you can view the same information in different ways. So why not stay with analog? The primary advantage to digital information storage and transfer is ease of manipulation. It can also be more readily checked for accuracy. A simple count and compare of the 1s and 0s against a known value can be performed at intervals, ensuring a degree of veracity that is hard to reproduce - certainly on the same scale - using analog data. In fact, digital data is simply easier to work with. Error correction, loss reduction - you name it, digital's got the advantage. Digital streams can also be converted to analog and vice versa, so the appropriate mix can be found to do the task at hand.

There's discussion here on digital data, here on analog vs digital music, and here is a crash course on digital from PBS for further reading.