The process of light curving all around the edges of tiny barriers, and therefore its invasion into the region of geometric shadows, is known as the diffraction of light.
Diffraction is divided into two categories. 2.1 Fresnel diffraction 2.1.1 The light from a point source causes Fresnel diffraction. 2.1.2 The incident and diffracted wavelengths in Fresnel diffraction are spherical or cylindrical. 2.1.3 Diffraction occurs because the source and screen are separated by a finite distance from the obstruction. 2.1.4 The point source's incident beam will be divergent, whereas the diffracted beam will be convergent. 2.2 Fraunhofer’s diffraction 2.2.1 both the incident wavefront and the diffracted wavefront constitute planes. 2.2.2 The incident and diffracted beams are aligned in the same direction. 2.2.3 The distance between the source and the screen is unlimited.