Okay, so you know how sometimes adults buy pretty pictures to put on their walls called wallpaper? Well, some people who make these wallpapers get charged something called a tax. This tax is like when you have to give your teacher some stickers or candy to use the classroom supplies. Except it's not stickers or candy, it's money that goes to the government.
Then, the government uses this money to do things like build playgrounds or make sure everyone has clean water to drink. So, the people who make wallpapers get charged a little bit of money to help make the world a better place. And that's what we call the wallpaper tax!