Okay kiddo, do you know how when you're talking on the phone, sometimes your voice gets really hard to hear or the call gets disconnected? That's because your phone is not good at picking up signals from far away places.
But have you ever noticed that when you move closer to a window or go outside, your phone gets better signals and your call gets clearer? That's because your phone can pick up signals better where there's less stuff in the way.
A cellular repeater helps to fix this problem by boosting and repeating signals coming to and from your phone. Think of it like a big megaphone that takes a signal from far away and makes it louder and clearer so you can hear it better.
So, a cellular repeater is like a machine that helps your phone get better signals and helps you have clearer phone calls, even when you're inside a building or far away from the cell tower.