Marvel Cinematic Universe is like a big, giant puzzle with lots of pieces that all come together to make a really cool picture. Imagine you have a bunch of toys that you like to play with, but each toy is its own story with its own characters and plot. Then one day, you decide to take all of your toys and play with them together at the same time. That's kind of like what Marvel Cinematic Universe is.
The story of Marvel Cinematic Universe is told over many different movies featuring lots of different superheroes like Iron Man, Captain America, Black Widow, Hulk, Thor, Spider-Man, and many more. They all live in a world where there are lots of bad guys and problems to solve, but they work together to save the day.
Each movie is like a small piece of the puzzle, but when you put them together in order, they tell a bigger story. For example, Iron Man is the first movie in the Marvel Cinematic Universe, and it introduces us to Tony Stark, a rich man who invents an iron suit that gives him superpowers. Then, in the next movie, we meet more heroes and learn more about the evil plots of the bad guys they have to fight.
As you watch more movies, you begin to see how the characters' stories intertwine with each other. For example, in The Avengers, all of the heroes come together to fight a big bad guy named Thanos. The events of that movie then lead into the next movies in the series, like Avengers: Age of Ultron and Avengers: Infinity War.
So, Marvel Cinematic Universe is like a really big and awesome story with lots of superheroes fighting together to save the world from bad guys. It's like having all of your favorite toys play together in one big adventure!