How is diffraction of the electromagnetic spectrum used?

Question

exactly as it says on the tin. How is diffraction of the electromagnetic spectrum used?

Answer 1

well since the electromagnetic spectrum includes light then a rainbow is one example

production of monochromatic light beams

fibre-optics

radio signals in the HF band are bounced around the world by diffraction in the ionosphere mostly in the F layer

diffraction is caused by a change in density whether in air or glass or water