what is the early devices that is use in all the quiz shows game interlock buzzer?

mac: what is the early devices that is use in all the quiz shows game interlock buzzer?
now a days quiz shows are using devices or equipments that are controlled by a microcontroller chip. may i know the functions or the operations of this early devices and the difference by using a microcontroller.

Answers and Views:

Answer by tinkertailorcandlestickmaker
I’ll say electromagnetic relay, but I’ not sure I really understand the question.