Okay kiddo, a blackout is when a TV channel is not allowed to broadcast a certain game or show. It's like when your parents tell you that you can't watch your favorite show because it's not appropriate for your age.
Sometimes there are blackout rules in place for certain events or games, which means that the TV channel in your area cannot show it. This might happen if the game is being played in a different city and the channel in that city wants people to go to the game in person instead of watching it on TV.
It's like if you and your friend were playing a game at school and only the kids in your class were allowed to watch, but kids from other classes couldn't come and watch because it would be too crowded.
It can be frustrating when there's a blackout and you really wanted to watch the game or show. But sometimes it's just the rules we have to follow so everyone can enjoy the event in the best way possible.