Roller shutter

A roller shutter is like a big, thick curtain made out of metal or strong plastic that covers windows or doors. It rolls up and down on a track, kind of like a paper towel roll. When it's down, it covers the window or door to keep things out like rain, wind, or people who shouldn't be coming in. When it's up, it rolls up and away, so you can see out the window or walk through the door. It's like a giant shield that you can control!