What is a green box pedal?

Could you please explain what a green box pedal is? I'm not familiar with this term and I'm curious to know its function and significance in the world of music or audio production. Is it a specific type of effect pedal, perhaps used to enhance the sound in a particular way? Or does it serve a different purpose altogether? I'd appreciate it if you could provide a concise yet informative description of the green box pedal and its applications.