Regular reflection, also known as specular reflection, is a type of reflection that occurs when a beam of parallel light rays is incident on a smooth and plane surface, and the reflected rays are also parallel. The angle of reflection of the light is equal to the angle of incidence and on the opposite side of the normal to the point of incidence. This behavior is described by the law of reflection, which states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. Regular reflection occurs when light reflects off a very smooth surface and forms a clear image. In contrast, irregular or diffuse reflection occurs when a beam of parallel light rays is incident on a rough surface, and the reflected rays scatter in different directions. In this case, the angle of reflection of the light is equal to the angle of incidence. Reflection from a polished surface is called regular reflection, while reflection from a rough surface is called diffuse reflection.