Okay kiddo, have you ever heard of copyright infringement? It's when someone uses something that belongs to someone else without their permission. For example, if you take someone's toy without asking them, that's not nice and you could get in trouble.
The same thing can happen online, but instead of toys, it's things like music, movies, and books. People can share these things on the internet, but sometimes they do it illegally, without the owner's permission.
Now, sometimes it's hard to know who is doing the sharing, because it could be anyone. So, the government made a law called the Online Copyright Infringement Liability Limitation Act to help protect people who run websites.
This law says that if someone shares something illegally on a website, the website owner can't get in trouble if they didn't know about it. But if they did know about it and didn't try to stop it, then they could get in trouble.
It's kind of like if you have a friend over to play and they take one of your toys without asking. If you didn't know about it, then you can't get in trouble. But if you did know and didn't tell them to stop, then you could get in trouble too.
So, this law helps protect website owners from getting in trouble for something they didn't know about. But it also tells them that they need to try to stop people from sharing things illegally on their websites.