A delay pedal is an effects unit used by musicians, particularly guitarists, to create a repeating echo of the original sound. It works by recording the input signal and playing it back after a set period, allowing for various delay times and feedback levels. This effect can enhance musical performances by adding depth and texture to the sound. Delay pedals often feature controls for adjusting the delay time, feedback, and mix level, enabling users to customize the effect to their liking. They are commonly used in genres like rock, pop, and electronic music, making them a popular choice among artists and bands, including The Edge from U2.