A square wave is a type of waveform that alternates between two levels, typically high and low, with a sharp transition between them. This creates a signal that looks like a series of squares when graphed over time. Square waves are commonly used in electronics and signal processing because they can represent digital signals, where the two levels correspond to binary values of 1 and 0. Square waves can be generated using various electronic components, such as oscillators and microcontrollers. They are important in applications like pulse-width modulation and timing circuits, where precise control of on-off states is required. The frequency of a square wave determines how quickly it switches between its high and low states.