As an integral part of guitar (and bass) effects, the loop pedal, also known as a looper or loop station, lets you record the instrument’s signal and loop it indefinitely. Unlike Delay, which is an effect used to echo a sound, a looper is a tool that repeats a recorded signal identically.
The Wah-Wah pedal is a frequency filter controlled by foot movement. By changing the position of the pedal, the musician changes the frequency, equalizer setting, getting a “croaking” sound. This is a parametric filter, in which the center frequency of the peak is changed using the pedal.