ELI5: Explain Like I'm 5

Transfer function

Transfer function is a way to show the relationship between an electrical signal that goes into a system and an electrical signal that comes out. It usually looks like a graph with two lines (one going up and one going down). The line going up shows how much the signal coming out increases when the signal going in increases, and the line going down shows how much the signal coming out decreases when the signal going in increases.