How does a prism produce rainbow colours?

The sunlight which seems to be white is composed of seven colours. Issac Newton, father of physics proved it for the first time in 1666. He demonstrated with the help of a glass prism that sunlight comprises violet, indigo, blue, green, yellow, orange and red (VIBGYOR) colours.

The question arises: what is a prism and how does it separate the seven colours of white light?
Prism is made of transparent glass with three faces. Two of them are triangular and remaining one is rectangular, each edge making an angle of 60 degree. If we see an object through a prism, it will look multi-coloured. Whenever a ray of light passes through a prism, it deviates from its path and bends towards the base of the prism. This property of bending of light from its path while passing from one medium to another medium is called 'refraction' of light. As already said, white light is composed of seven colours. While coming out of the prism, these different colours deviate at different angles. These colours constitute what we call the spectrum. The red colour deviates least from its path whereas violet colour deviates maximum. That is why the red colour occupies the uppermost part of the spectrum, while violet the lowermost. Other colours are in between these two. Separation of white light into seven different colours is called the dispersion of light. These are the same seven colours seen in a rainbow. This is how a prism disperses white light into the seven rainbow colours.