Why can you see rainbows at the edge of waterfall?

Rainbows can be seen at the edge of a waterfall due to the refraction, reflection, and dispersion of sunlight in the water droplets that form mist. When sunlight hits these droplets, it bends and splits into its constituent colors, creating a spectrum that appears as a circular arc. The angle of the light and the position of the observer relative to the waterfall and the sun are essential for a rainbow to be visible. Typically, rainbows are seen when the sun is behind the observer and the mist is in front.