View Pass or Render Pass
A Pass (Render Pass) is the term used for rendering output intended to be used as an element within a composite, as opposed to a standalone image. Rendering engines use passes internally for many different shading operations. These passes may be useful to compositors, and as such are made available for that use via user-specified rendering passes.
Rendering passes offers greater control over the final shot, as well as more experimentation and faster shot turnaround times. Depending upon the passes available for a shot, the compositor can change colors, modifiy the gamma or tone, or even “relight” a shot. Further, effects such as motion blur, glows, depth of field and so on can be added in compositing (or “post”) and are typically much faster and of similar quality, to the 3D render.