Butterfly life Cycle starts from the eggs. The eggs usually be on the leaf surface. And the eggs will hatch and will be a caterpillar.
A caterpillar will eat for days. It will stop eating when it will change being a pupa. And a pupa periods go on days. If it's already, a butterfly will come out from a pupa. And a butterfly will be an adult butterfly. After that, an adult butterfly will have some eggs. And from some eggs, butterfly life cycle will start again.
More and less something like that.