What is a digital signal?

A digital signal is defined as the representation of an analogue signal using binary data. This means that it translates continuous information (which can assume an infinite number of values) into a format that can be represented by discrete values, typically zeros and ones, in a binary system.

This conversion is essential for various applications in digital computing and telecommunications, as digital signals are more robust to noise and interference than their analogue counterparts. By encoding analogue information into binary, devices can process, store, and transmit data more reliably.

In contrast, the other options do not accurately describe a digital signal. For instance, a digital device's representation does not encapsulate the essence of a digital signal itself, and a signal that operates in real-time or uses continuous values relates more to characteristics of analogue signals rather than digital ones.