An identification document is a special piece of paper or card that proves who you are. It's like a secret code that only you know and shows other people that you are really you, just like a superhero has a secret identity that they use to be recognized.
Usually, an identification document has your picture on it, along with your name, your birthday, and other important things that show that you are a real person. This helps other people, like your parents or the government, be sure that you are who you say you are.
Sometimes, you need an identification document to do things like open a bank account or get a job, just like how a superhero needs their secret identity to do superhero things. So, it's important to keep your identification document safe and to only show it to people you trust, just like how a superhero keeps their secret identity a secret.