We all have seen a rainbow, one day or the other. It is a very beautiful sight. A rainbow is an arch or a bow of seven colours, that appears in the sky.
We see a rainbow only when there is sunlight and rain at the same time.
It appears when raindrops act as prisms.
They split the white sunlight into its basic colours. The rainbow is not a real thing but an illusion. In ancient times people believed it was the bow of Indra, The king of Gods.
Some others said it was a bridge created by God to connect heaven and earth. Do you like to see a rainbow without rain?
Then take a mouthful of water, face the sun and blow the water out as fine spray. You will see a small rainbow before you.