The life cycle of a butterfly begins as an egg, which hatches into a caterpillar, grows larger, spins a pupa [ shell casing ] where it does chrysalis which is the changing of the form of caterpillar to Butterfly inside the pupa. When the Butterfly emerges from the pupa, it does not live very long, it will reproduce before it dies.
An egg to larva to pupa to adult.
Here is a page that discusses the life cycles of butterflies. Www.butterfliesandmoths.org/faq/lifespan
Egg (larva), hatches into a caterpillar, grows bigger, pupa stage, becomes butterfly after the pupa. The butterfly will not live really long. It can only live for several weeks.