This is the part you see through. It's the glass, or other transparent material, that forms the panes of windows, skylights, French doors, and the like.
In nature, everything has a purpose. This is a community of living things-animals, plants, and microorganisms-together with the environment in which they live. All exist in a delicate, complex, interdependent balance; any outside influence that disrupts one aspect-the removal of trees from a forest, for instance-can have an impact on the entire ecosystem.