How does GPS actually pinpoint your exact location on Earth?

GPS uses signals from satellites to figure out where you are on Earth, like how a map helps you find your way home.

Imagine you have a special watch that talks to space, and those space friends tell you exactly when they sent their messages. GPS works the same way, but with satellites instead of watches.

Each satellite sends out a signal that travels through space at the speed of light. Your phone or device gets this signal and counts how long it took to arrive. Since all signals travel at the same speed, your phone can tell how far away each satellite is.

Now imagine you're playing hide-and-seek, if you know how far away four friends are from where they’re hiding, you can guess exactly where you should be to find them! GPS uses four satellites to do this, so it can figure out the exact spot on Earth, your location.

Just like knowing how far away one friend is only tells you part of the story, having just one satellite would give you a big circle of possible spots. With two, that becomes a line where you could be. But with four, it narrows down to one specific point, your location!