What is "roller shutter"

n. A shutter (for a window or door) consisting of a series of horizontal sections that are hinged together and attached to a roller at the top

A roller shutter, roller door or sectional overhead door is a type of door or window shutter consisting of many horizontal slats (or sometimes bars or web systems) hinged together. The door is raised to open it and lowered to close it. On large doors, the action may be motorized. It provides protection against wind and rain. In shutter form, it is used in front of a window and protects the window from vandalism and burglary attempts.