Buoyancy is the force that pushes the object to float and it depends on density. Density is when a lot of subject is together in a little space. There is negative buoyancy if the object is denser than water. There is neutral buoyancy and this happens when the density of water is the same as the density of the object. Positive buoyancy is when you push an object in the water and the force of the buoyancy pushes the object back up. Positive buoyancy is when water is denser than the object. The buoyant force is equal to the displace water. If the density of the object is more than 1 g/ml the object will sink. If the density is less than 1 g/ml the object will float, because the density of water is 1 g/ml. Stability is when the object is stable and when the object is stable it does not move a lot.