Which of the following best describes the characteristics of digital voltage?

Digital voltage is characterized by its ability to change quickly between different voltage levels, often corresponding to binary states represented in digital circuits (e.g., high and low states). This behavior is fundamental for digital systems which operate using discrete values rather than a continuous range.

In digital electronics, the voltage levels are defined in such a way that they represent specific logical states, typically a '1' (high) and a '0' (low). The rapid transitions between these states allow digital devices to perform complex computations and process information efficiently.

The other characteristics described in the options do not accurately represent digital voltage. For example, steady variation over time corresponds more to analog signals, which change smoothly rather than in discrete steps. Continuous voltage without interruption also refers to analog systems, where the signal can take on any value in a given range. Finally, digital voltage is distinct from AC voltage, which fluctuates sinusoidally and does not represent discrete states such as those used in digital circuits. Thus, the characteristic that best describes digital voltage is its ability to change quickly between different levels.