Reflection, without diffusion, in accordance with the laws of geometrical optics; as in a mirror.
Reflections from a surface that are based on the geometric properties of a wave (no surface phenomenon). May be thought of as associated with a ray which arrives I at a surface at a given angle and bounces forward at the same angle (as a ball would bounce or as light would reflect from a mirror). In contrast, with non-specular reflection, a ray striking a surface at an angle reflects off over a wide range of angles with a wide variety of rays.
Reflection from a smooth surface, in which the light ray leaves at the same angle at which it came in.