Without quoting directly from the text, give me a summary of how rainbows are formed.

Rainbows are formed when light shines through water droplets, creating an optical phenomenon. The light is bent and reflected, creating a multicolored arc. Rainbows created by sunlight can be found in the sky, opposite the sun. Rainbows are usually observed as an arc, but can appear as full circles. A double rainbow appears when the light shining through each water droplet is reflected twice, creating a second arc, with the colours appearing in reverse order. The colors of the rainbow include; red, orange, yellow, green, blue, and violet. The colors appear in order of their wavelength, from longest to shortest.