Diffraction
1. Diffraction is the process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture or across an edge, typically accompanied by interference between the wave forms produced.
2. In physics, diffraction is a change in the direction of a sound wave or a light wave caused by the presence of an obstacle in its path.
We classically think of light as always traveling in straight lines, but when light waves pass near a barrier they tend to bend around that barrier and become spread out. The definition of diffraction is the spreading of waves as they pass through or around an obstacle. More specifically when applied to light, diffraction of light occurs when a light wave passes by a corner or through an opening or slit that is physically the approximate size of, or even smaller than that light’s wavelength.
The terms diffraction and scattering are often used interchangeably and are considered to be almost synonymous. Diffraction describes a specialized case of light scattering in which an object with regularly repeating features (such as a diffraction grating) produces an orderly diffraction of light in a diffraction pattern. In the real world, most objects are very complex in shape and should be considered to be composed of many individual diffraction features that can collectively produce a random scattering of light.
Isaac Physics https://isaacphysics.org/
Google’s English dictionary by Oxford Languages https://languages.oup.com/google-dictionary-en/
Olympus-Lifescience https://www.olympus-lifescience.com/en/microscope-resource/primer/lightandcolor/diffraction/