The center of curvature is the center point of a sphere from which a curved mirror or lens is derived.
Topic 6.5: 6.5 Images from Lenses and Mirrors
Center of Curvature (C) cheat sheet for homework
The distance between the center of curvature and any point on the curved surface.
Concave Mirror/Lens: A mirror/lens that curves inward, with its center of curvature in front.
Convex Mirror/Lens: A mirror/lens that curves outward, with its center of curvature behind.