Why an object has a different weight in air from its weight in water?

An object's weight in air differs from its weight in water due to the buoyant force exerted by the fluid. When submerged in water, the buoyant force acts upward against the weight of the object, effectively reducing its apparent weight. This phenomenon is described by Archimedes' principle, which states that the buoyant force is equal to the weight of the fluid displaced by the object. Consequently, while the object's mass remains constant, its weight appears less in water than in air.