What is regular r

When light falls on a highly polished surface such as a mirror, reflects most of the light rays falling on it. The plane surface seems shiny from a certain direction. If we change the direction of mirror the mirror shines from another direction. When light beam falls on a shiny surface they bounce back into the same medium in a certain direction, this phenomenon is called regular reflection.

When light falls on rough surfaces, dust & smoke, the light is reflected and spread in every direction. The phenomenon of spreading light in all directions by the rough surfaces is called diffused reflection.