Magic Lantern is like a magic tool that helps your camera do things it normally can't do. Do you know how your toy cars have some extra things like doors that can open or the wheels that can rotate in different directions? Magic Lantern is like that but for cameras. It is a special software that people can install on their camera to unlock extra features that are not normally available.
Just like how you need to have special keys to open some doors, you need to have the right Magic Lantern software that matches your camera to open its new features. Magic Lantern can help your camera take better pictures, videos, and even do things like timelapses (like watching a flower grow over time really quickly). It even lets you monitor your camera's battery life, settings, and other information on a special screen.
Magic Lantern is like a coach that helps your camera do its best so that you can take amazing pictures and videos just like a grown-up photographer! It is important to remember that while Magic Lantern is really cool, it is a tool that should be used carefully, and only by grown-ups who know what they are doing.