PURPOSE OF USING BRACINGS

Structural strength, it allows the spread of the forces among more surfaces and a greater area. For example, if you build a square and apply pressure to a side, you'll notice the weak fail point will tend to be at the corners.(it will collapse & twist diagonally). Attaching pieces in a cross pattern connecting the corners together will greatly increase the structure's strength/rigidity as you will see if you again apply pressure to a side.