How Cell Phones Reveal Your Location - Computerphile?

Cell phones can tell where you are, just like a friendly friend who knows your favorite spot at the park.

Cell phones use towers, big buildings that send and receive messages, to figure out where you are. Imagine you're playing hide-and-seek with your friend, and every time you shout, they get closer to finding you. That's like how cell towers work: the more towers your phone talks to, the better it can guess where you are.

Your phone sends a message to nearby towers, and each one replies. By looking at how long it takes for those messages to come back, your phone can tell how far away each tower is. With that information, it draws a little map around you, like drawing circles on paper with the towers in the middle. Where those circles overlap is probably where you are!

Sometimes, phones also use Wi-Fi or even the GPS inside them, just like having more friends help find you in hide-and-seek!