What is a square wave

A square wave is a non-sinusoidal waveform commonly associated with electrical and signal processing. An ideal square wave has only two values "high" and "low". A signal whose waveform of current or voltage is rectangular is a rectangular wave signal, and the time ratio of a high level in a waveform cycle is called a duty cycle, which can also be understood as the ratio of the effective release time of the circuit to release energy to the total release time. . A rectangular wave with a duty cycle of 50% is called a square wave, and the square wave has a low level of zero and negative. When necessary, it can be stated that "low level is zero" and "low level is negative".