^Concave mirror & Convex lens

A concave mirror has outer or bulged side polished. A convex lens is thick near center & thin near the edges. They have following common features

1. Real focus
2. Converge light rays striking on them
3. Positive optical power
4. Can form several type of images such as diminished, enlarged, same size, real virtual image of a real object
5. Can’t form a diminished & virtual image of a real object.