Okay kiddo, so a mansion is a really big and fancy house that only some people can afford. Sometimes, when people sell their mansion, the government wants to charge them extra money called a mansion tax. The government does this to try and get more money to help pay for things like parks, schools, and roads. Some people think this tax is a good idea because the people who own mansions usually have a lot of money, so they can afford to pay a little bit extra. Other people don't like this tax because they think it's not fair to charge extra just because someone has a really nice house. That's why some places have a mansion tax and others don't.