Define the term 'buoyancy'.

Buoyancy refers to the upward force that a fluid exerts on an object submerged in it or floating in it, which opposes the object's weight. This force allows objects to float or rise in a fluid and is a fundamental principle of fluid mechanics. When an object is placed in a fluid, it displaces a volume of fluid equal to its own submerged volume, and according to Archimedes' principle, the upward buoyant force exerted on the object is equal to the weight of the fluid that is displaced. This means that if the buoyant force is greater than the weight of the object, the object will rise or float. Thus, this definition captures the essence of buoyancy as the force responsible for an object's ability to float or remain suspended in a fluid.