Thanks to what optical phenomenon can a rainbow be observed after rain?

Rainbow is an atmospheric optical phenomenon – dispersion that is observed when the Sun illuminates many water droplets during rain or fog, or after rain. As a result of the refraction of the sun’s rays in water droplets during rain, a multi-colored arc appears in the sky. A rainbow also appears in the reflected rays of the Sun from the water surface of sea bays, lakes, waterfalls or large rivers. Such a rainbow appears on the banks of water bodies and looks unusually beautiful. Rainbow arcs are multi-colored, but they need sunlight to appear. Sunlight appears to us to be white, but is actually composed of the colors of the spectrum. We are used to distinguishing seven colors in a rainbow – red, orange, yellow, green, blue, blue, violet, but since the spectrum is continuous, the colors smoothly pass into each other through many shades.