The force that allows us to float is called buoyancy. Buoyancy is the upward force exerted by a fluid (liquid or gas) that opposes the weight of a partially or fully immersed object. In the case of humans floating in water, the buoyant force is exerted by the water and is equal to the weight of the water displaced by the person's body. This means that if the person's body is less dense than water, the buoyant force will be greater than the weight of the person, and they will float.