Blonde Girl Wearing Black Stockings Outside At The Wall

A wall is a usually solid structure that defines and sometimes protects an area. Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air. There are three principal types of structural walls: building walls, exterior boundary walls, and retaining walls.
Building walls
Building walls have one main purpose: to support roofs and ceilings. Such walls most often have three or more separate components. In today's construction, a building wall will usually have the structural elements (such as 2×4 studs in a house wall), insulation, and finish elements or surface (such as drywall or panelling). In addition, the wall may house various types of electrical wiring or plumbing. Electrical outlets are usually mounted in walls.