The phenomenon of bouncing of light from a surface, back into the medium in which it was travelling earlier is called as reflection of light.
Reflection of light can be classified as-
1. Regular reflection- For a parallel incident beam of light if the reflected beam is also parallel, the reflection is called as regular reflection. It takes place at smooth shiny surfaces like mirror and polished metal surfaces
2. Irregular reflection- For a parallel incident beam of light if the reflected beam is not parallel, the reflection is called as irregular reflection or diffused reflection. It takes place at rough surfaces like brick wall and road.