Digitizing: Sampling and Quantization

In order to be processed by a computer, a signal must be converted to a digital representation:

1. Sampling: The instantaneous value of the signal is measured at equally spaced time intervals.
2. Quantization: The samples are then rounded to the closest level from a finite set of output levels that the A/D converter device can represent.

The  is the series of numbers (corresponding to the levels) resulting from this process.