Okay kiddo, the United States Congress is kind of like a big group of grown-ups who make rules and decisions for our whole country. It's made up of two parts, the House of Representatives and the Senate.
The House of Representatives is like a big club with lots of members from all over the country. Each member represents a certain area called a district and is elected by the people who live there. They're kind of like the "voice" of the people in that area, and they work together to decide what laws should be made or changed.
The Senate is another group of grown-ups who work with the House of Representatives. But instead of having a lot of members from all over, there are only two from each state. So there are 100 Senators total. They also make laws and decisions, but they have a little bit different job than the people in the House of Representatives.
Both the House of Representatives and the Senate have to agree on laws before they become official, like when your parents have to agree on a rule before it becomes the rule for the whole family. And sometimes the grown-ups in Congress have to talk and argue a lot before they can agree on something. But that's okay because making decisions for a whole country is a big responsibility!
So that's the United States Congress, a really important group of grown-ups who help make our country a better place.