Owens Corning's "Roofing Basics: The Anatomy of a Roof" tool delivers a user-friendly way to learn about your roofing system. Their interactive site delivers a high-level view of an example roof, and allows you to get more in-depth information about each component.

From their site:

Roofing Basics: The Anatomy of a Roof
I think I need a new roof. Now what? First of all, don’t worry. Owens Corning™ Roofing is here to help. Our entire Roofing Basics section is designed to give you the information you need.

Want to try it out, click here to visit the online tool.