All hulls are hollow, so they are lighter, more buoyant than gravity and can float on the water. The ship can move forward because of the propulsion of the machine or the rowing of manpower.

A ship refers to a vehicle that uses the buoyancy of water and relies on the power of manpower, sails and engines (such as steam engines, gas turbines, diesel engines and nuclear power plants) to pull, pull, push, paddle or push propellers and high-pressure nozzles to move on water. In addition, civilian ships are generally called boats (called sampans in ancient times), wheels (boats) and boats, military ships are called boats (called sampans in ancient times) and boats, and small ships are called sampans, boats, rafts or boats, collectively referred to as ships, boats or boats.