Define a lintel as it's function as applied in construction?

A lintel is a horizontal beam that spans an opening, such as a doorway or window, in a building to support the weight of the structure above it. Its function is to distribute the load of the structure above the opening and prevent the walls from collapsing. Lintels are typically made of materials such as wood, steel, or concrete, and are essential for providing structural support and stability in a building.