Forces hold things together and push them apart and make things move or stop. You are held onto the earth by the force of gravity. Gravity is a force that gets stronger for things with more mass and the closer the objects are together. There are 3 other forces that we know about in nature: Electromagnetic, Strong, and Weak . Each of these forces is stronger than gravity for our small quarks. When you go to the subatomic world, you can see the quarks being affected by the forces, because there are other particles that carry the force from particle to particle. Learn more about each force.