ELI5: Explain Like I'm 5

Sinc function

The sinc function is like a kind of wave that goes up and down. It is made up of two parts: a bunch of up-and-down lines that look like steps, and a smooth curve that goes under the lines. The sinc function is used to show how things change in a smooth way over time. For example, it can be used to show how the sound of a song or the brightness of a light changes over time.