To obtain silk ,silkworms are cultivated and this is called sericulture or silk farming.
There are total four stages in the life cycle of silkworm:-eggs,larva/caterpillars,cocoons and adult moths.
The first stage is egg, the Caterpillar rises from the the egg then it spin a protective covering around itself called cocoons and after sometimes from cocoon we get adult moths
Final Answer: Silk worms are cultivated to obtain silk in sericulture.