Okay kiddo, imagine you love singing and dancing and you put on a big show with all your friends in your backyard. Now, sometimes people make bigger shows and they perform in big theaters in New York City. These shows are called Broadway shows and they are very expensive and fancy!
But sometimes, people make smaller shows that can't afford to perform in those big theaters. These shows are still really good, but they perform in smaller theaters around New York City, these are called Off-Broadway shows.
Off-Broadway shows are for people who still love singing and dancing, but maybe can't spend as much money or maybe they like more unique shows. They are still super fun to watch with lots of singing and dancing, but sometimes they can also be more experimental or different from what you usually see on Broadway.
In summary, Off-Broadway shows are like smaller versions of Broadway shows that you can still watch and have fun with, but they are in smaller theaters and sometimes they have more unique stories or performances.