Doorstop
A doorstop (also door stopper, door stop or door wedge) is an object or device used to hold a door open or closed, or to prevent a door from opening too widely. Alternatively, a doorstop can be a thin slat built inside a door frame to prevent a door from swinging through when closed. A doorstop (applied) may also be a small bracket or 90 degree piece of metal applied to the frame of a door to stop the door from swinging (bi-directional) and converting that door to a single direction (in-swing push or out-swing pull).
Usage
Holding doors open
A door may be stopped by a doorstop which is simply a heavy solid object, such as a rubber, placed in the path of the door. These stops are predominantly improvised. Historically, lead bricks have been popular choices when available. However, as the toxic nature of lead has been revealed, this use has been strongly discouraged.
Another method is to use a doorstop which is a small wedge of wood, rubber, plastic, cotton or another material. Manufactured wedges of these materials are commonly available. The wedge is kicked into position and the downward force of the door, now jammed upwards onto the doorstop, provides enough static friction to keep it motionless.