When light falls on an object, if it is obstructed and returns back, it is called reflection of light. When light falls on an object and do not comes back then that is called absorption of light. The light wave could be absorbed by the object, in which case its energy is converted to heat. The light wave could be reflected by the object. And the light wave could be transmitted by the object.
Observe these two pictures below; the first picture is of smooth a surface (mirror or steel plate). The second one is of rough surface (steel plate used for a long time or a page of paper). What are the two pictures about?
The first picture is of regular reflection from the mirror. Here the light falls on the surface at an angle and returns back meting exactly the same angle. This fall of light on a surface is called incidence and obstruction of light by the surface and its returning back is called the reflection. Here the angle of incidence is equal to the angle of reflection. The incidents rays are parallel to each other as well as the reflected rays are parallel to each other.
In the second picture incident rays are parallel to each other but the reflected rays are not parallel to each other, this type of reflection is called irregular or scattered or diffused reflection.