The life cycle of a butterfly:
The butterfly lays its egg on the leaves of the plants. The new born that comes out of the egg is called a larva or caterpillar. It actively feeds and gains size.
When the larva stops moving and eating and is called a pupa. It is a resting stage. The pupa is covered by a cocoon. During this stage, it attains the features of adult hood. After attaining adulthood the pupa comes out of the cocoon after breaking it as an adult butterfly.
The stages of development are: egg, larva, pupa, adult.