Reflection

Law of reflection:
The angle of incidence is equal to the angle of reflection: $\theta$_i = $\theta$_r
Specular (regular) reflection
On plane surfaces, all incoming light gets reflected in the same way.
=> one can see images of light sources
=> used for the construction of mirrors
Diffuse (irregular) reflection
The reflecting surface is irregular. Even though the law of reflection is still correct for every point, the reflected light bounces off in many directions.
=> illuminated surfaces without mirror images.