ELI5: Explain Like I'm 5

dip switch

A dip switch is a small switch that you can use to turn something electronic on or off. It looks kind of like a button and usually comes in a group of several switches spread out together. The name comes from the fact that you can dip the switch in and out of its housing - meaning you can switch it from on to off or from off to on. They're used to customize some electronic devices, such as TVs, computers and toys.