The National Reconnaissance Office (NRO) is like a big eye in the sky that helps the United States government see things happening around the world that they might not be able to see otherwise.
Imagine you're in a big field with your friends, and you want to know what's happening on the other side of a big hill that you can't climb. But then, your friend lets you borrow their super awesome binoculars that can see over the hill, and you can see everything that's happening on the other side!
That's what the NRO does, except they use really big and high-tech satellites with cameras on them that can see things happening on the ground from way up in space. These satellites are so powerful that they can even see things like the make and model of a car or the text on a sign from miles up in the sky!
The information that the NRO gathers from these satellites helps the government understand what's happening in other countries, like if they're building weapons, or if there might be a natural disaster coming. This information is really important for making decisions to keep the United States safe and protect its people.