Render Elements are a way to break out renders into their component parts such as diffuse color, reflections, shadows, mattes, etc. This gives fine control over the final image when compositing or image editing to re-assemble the component elements. Render elements are also sometimes known as render passes.
Render elements are generated at render time based on the user's selection before rendering. Most render elements have parameters that can be customized to further assist the composting process. These parameters are described on each render element's individual page, along with common uses and any notes on their generation and usage.
