A long time ago Syracuse , Ancient Greece there was a was a great mathematician named Archimedes.One day when he was taking a bath he discovered something life changing.When he got in the some water got displaced and it overflowed over the bath tub. Archimedes discovery got him thinking He was so excited that he ran
through the streets without any clothes on shouting Eureka Eureka this meant I have found it in Greek.
He figured out that if you put something in water and it is lighter than the amount of water being displaced,the objected will float. This is own as buoyancy or the Archimedes principle.So if the object can float it is buoyant.