What is buoyancy

What is buoyancy ?  

A long time ago, in syracuse Ancient Greece there was a great mathematician named Archimedes. One day when he was taking a bath, he discovered something life changing. When he got in some water got displaced and it overflowed over the bath tub.

Archimedes’ discover got him thinking. He was so excited that he ran thru the streets without any clothes on, shouting “ Eureka ! Eureka ! “ “ This means’ I found greek”