MIRRORS - plane and spherical mirrors

 Mirrors are polished or smooth surfaces, normally a glass coated with a metal amalgam. It can reflect clear image.

Plane mirrors 

A plane mirror is a mirror with a flat reflective surface. 

Spherical mirrors 

Spherical mirrors are mirrors which have reflective surface either curved inwards or outwards. It can be considered as a part of a sphere. A spherical mirror, whose reflecting surface is curved inwards (facing towards Center of sphere) is called as concave mirror. A spherical mirror in which reflecting surface is curved outwards is called as convex mirror 

In the diagram above shaded part is back side of the mirror