What is digital to analog?

Answer 1

A digital input (in the form of a number) is converted into analog format, which could be a voltage or a signal frequency, for example. An example, which most people would be familiar with, is your touch tone phone. When you press a key on the phone, that is a digital input. The output is actually 2 frequencies mixed together (analog signal). Each row of keys on your phone is associated with a frequency, and then each column of keys is associated with a frequency. The two frequencies combined represent the row and column of the key that was pressed. At the phone company, they use analog filters to determine what frequencies were generated by your phone, and from that, determine which key was pressed (this is Analog to Digital conversion).