Here's a breakdown:

* Buoyancy is an upward force exerted by a fluid (liquid or gas) that opposes the weight of an immersed object.

* This force is caused by the difference in pressure between the bottom and top of the object submerged in the fluid. The pressure at the bottom is higher due to the weight of the fluid above it.

* If the buoyant force is greater than or equal to the weight of the object, the object will float. If the buoyant force is less than the weight of the object, the object will sink.

Let me know if you'd like more detail on how buoyancy works!