Water displacement is a principle that explains how an object submerged in water pushes aside or displaces a volume of water equal to its own volume. This concept is often demonstrated using the Archimedes' principle, which states that the buoyant force on an object in a fluid is equal to the weight of the fluid displaced by the object. When an object is placed in water, it will sink or float based on its density compared to that of water. If the object's density is less than that of water, it will float; if it is greater, it will sink. This behavior is crucial in various applications, including shipbuilding and hydrometry.