Answer and explanation:
On a flat, smooth surface, such as a flat mirror, all rays that strike the same direction will be reflected at the same angle.
Parallel rays that fall on a flat surface will remain parallel after reflection. The reflection on these smooth surfaces is called specular reflection.
When the surface is irregular, such as a curved or rough surface, the rays that appear at different positions on the surface arrive at different angles of incidence, because there are normal changes along the surface.
The angle of reflection remains the same as that of incidence, but they are reflected at different angles for those looking at the surface. This type of reflection is called diffuse reflection.