The force acting on a body fully or partially immersed in a liquid is called buoyancy.

Here's a breakdown:

* Buoyancy is an upward force exerted by a fluid that opposes the weight of an immersed object.

* This force is equal to the weight of the fluid displaced by the object.

* The principle that explains this is Archimedes' Principle.

Let me know if you'd like to know more about Archimedes' Principle!