corners essentially

A corner is:

The point shaped by the intersection of two or more surfaces; an angle. The space or surface comprised between two converging walls or lines near their meeting.’

Two walls meet, join and create a corner, the being is created by the convergence of two other entities. When the surfaces come together the intersection is made up of precise geometric angles. There is nothing haphazard, a corner is made from deliberate, specific and precise measurements. They have to be there for a structure to exist, and yet in a room they are ignored, unseen.