What is the job of the branches in a tree?

A tree branch holds leaves which in turn catch the suns light which the tree needs to produce the fuel it needs to grow. The leaves and branches on a tree also catch water from rain and this water can cause the soil around the tree to be wetter. as well as this the shadow of the branches will cause a slowing in the evaporation of water from around the base of the tree. besides the branches catching the sunlight from above, branches also deny adequate sunlight for competing plants around the base of the tree to thrive further strengthening its position.