This tag is for questions relating to reflection, the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. A familiar example of reflection comes from water waves; as the waves travel they reflect off objects that are floating in the water, and also reflect off the walls of the container holding the water.

When a wave reaches the interface between two different media, typically some of the wave will bounce back into the original medium. This process is known as reflection.
A familiar example of reflection is optical reflection in mirrors, where light waves reflect off a smooth surface.
The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected.
Light reflects from a smooth surface at the same angle as it hits the surface. For a smooth surface, reflected light rays travel in the same direction. This is called specular reflection. For a rough surface, reflected light rays scatter in all directions. This is called diffuse reflection.