Okay kiddo, have you ever seen those seats in a movie theatre or on an airplane that are able to fold up and down? That's called a folding seat!
It's like a regular seat, but it has special hinges that let it bend in half in the middle. When you want to use the seat, you just pull it down and it unfolds into a regular seat shape. When you don't need it, you can fold it back up so it takes up less space.
Folding seats are handy for places where space is limited, like on airplanes or in small theatres. By having seats that can fold up when not in use, more people can fit in the space comfortably.