Rainbows are one of the most beautiful natural phenomena there is. Most of us are familiar with how rainbows form—we know to look for them after a rain when the sun peeks through the clouds. But what most people don't know is that there is more than one kind of rainbow.

There are 12 different kinds of single arc rainbows that are decided based on the colors, strength of the bands, and supernumerary bows that appear, or don't appear, in the arc.

The Short Answer: A rainbow is caused by sunlight and atmospheric conditions. Light enters a water droplet, slowing down and bending as it goes from air to denser water. The light reflects off the inside of the droplet, separating into its component wavelengths--or colors.

Twinned rainbows The rarest type of rainbow start from the same base but them split along the arc to form a primary and secondary rainbow. Twinned rainbows are formed when sunlight is refracted after coming into contact with two rain showers which have different size of droplets from each other.