A wall simply provides protection from the outer environment. It is a structure that defines an area, carries a load, or provides shelter or security. There are many kinds of walls: Defensive walls in fortification. Walls in buildings that form a fundamental part of the superstructure or separate interior sections, sometimes for fire safety. Sometime wall simply is not understood as the boundry of house because there are lots of enormous wall. For example Trump wall between Mexico and USA(to be built), The Great Wall of China etc.