A door frame is the structural element that surrounds a door and provides support for the door itself. It is typically made of wood, metal, or plastic and can be either pre-hung (meaning it comes with the door already installed) or built on-site.
Door frames are important because they provide structural support for the door, help to keep the door in place, and prevent drafts from entering the home. They can also be used to add decorative elements to a room.