Characteristics of an image formed in a plane mirror
i) Image formed in a plane mirror is upright
ii) Image formed in a plane mirror is virtual
ii) The image is of the same size as the object.
iv) The distance of the image from the plane mirror is equal to the distance of the object from the mirror
v) Image is laterally inverted

i) Sun rays entering a dark room through a small opening appears to travel in a straight line.
ii) Light from torch, headlights of cars etc appears to travel in a straight line
iii) Light from a projector travels in a straight line towards the screen.

Regular reflection:
When a beam of light falls on a smooth surface it gets reflected. This is called regular reflection or specular reflection.
i) After reflection at the individual reflected rays remain parallel.
ii) The angle of incidence and angle of reflection of each ray will be equal.
iii) The laws of reflection holds good for specular reflection
iv) Example: Reflection of light by a plane mirror
Irregular reflection:
When light falls on a rough surface, the light rays are reflected at different angles. This is called irregular reflection or diffuse reflection,
i) In this reflection each individual ray meets the surface which has a different orientation
ii) The reflected rays go in many directions and are not parallel to each other.
iii) The angle of incidence and the angle of reflection of each ray are not equal.
iv) Example: Reflection of light from a wall