ELI5: Explain Like I'm 5

Spread spectrum

Spread spectrum is a way of sending a signal, like sound or data, around a place. It's like sending messages through the air!
Instead of sending the signal all at once, spread spectrum breaks the signal into small pieces and sends them at different times. That way, even if something is blocking the signal, some of the pieces will still get through.
Spread spectrum also makes it hard for other people to hear the signal, so it's like a secret message! That's why it's used for important things like TV remotes, military radios, and cell phones.