Every stage of the pipeline has one job. Clipping decides what stays visible relative to the clip window.
Anything lying inside the window is retained, and anything outside is cut away, so the renderer never draws off-screen geometry. Resolution, transformation, and small-object culling are handled by other stages, not clipping.
Therefore clipping removes the parts of the image that fall outside the defined viewing area.
\[\boxed{\text{To filter out parts of the image outside the defined viewing area}}\]