Question

What is diffraction?

Answer 1

The tendency of a light ray to bend over a tiny opaque object which is in the path of light.

Answer 2

DIFFRACTION is the the phenomenon exhibited by wave fronts that, passing the edge of an opaque body, are modulated, thereby causing a redistribution of energy within the front: it is detectable in light waves by the presence of a pattern of closely spaced dark and light bands (diffraction pattern) at the edge of a shadow.