How is a square wave described?

A square wave is characterized by its unique shape, which alternates between two distinct voltage levels for equal durations. This means that the wave will rise to a maximum voltage, remain there for a set amount of time, then drop to a minimum voltage and stay there for the same duration before repeating the cycle.

This abrupt transition between high and low states gives the square wave its distinctive square-like appearance when graphed. This property is crucial in various electronic applications, especially in digital circuits, where it can represent binary states (0s and 1s) effectively.

The other descriptions do not match the characteristics of a square wave: a wave that varies continuously describes a sine wave or other types of continuous waves, a wave that remains constant at one voltage does not depict any oscillation, and a wave with a smooth sinusoidal shape also contradicts the sharp transitions seen in a square wave.