Okay kiddo, so imagine you want to play soccer but you need to make sure you are good enough to play with the best players. What do you do? You practice a lot and participate in games to show that you are good enough. Similarly, in the grown-up world of doctors, board certification is a way to show that a doctor is really good at what they do.
To become board certified, a doctor needs to complete their medical education and training in a specific field like pediatrics or cardiology. Then, they need to take a test called the board exam which is like a really hard soccer game. If they pass the test, it means they know everything they need to know about their field of medicine and they are “certified” to practice it.
Board certification isn’t mandatory, but having it shows that a doctor is really dedicated to their field and is committed to learning everything there is to know about it. Just like how you try to be the best soccer player you can be, doctors try to be the best they can be to help people feel better and stay healthy.