A rubber doorstop

A doorstop (or door stop or doorstopper) is a tool.

There are two types. One holds a door open (or stops it from closing), and the other stops the door from hitting a wall.

Doorstops that keep the door from hitting a wall can be put on the door, or on the wall, or on the floor in front of the wall.

Doorstops that are used to keep a door open come in two varieties:

• Attached to the door they are supposed to stop
• Wedges that can be put under the door they should stop, or anything heavy put in front of the door