1. Gravity: Gravity is a force of attraction between two objects with mass. It is the force that keeps the planets orbiting the sun and is responsible for the movement of objects on Earth and in the universe. Gravity is one of the four fundamental forces in nature.
2. Electromagnetism: Electromagnetism is the force of attraction or repulsion between two objects that have an electric charge. It is one of the four fundamental forces in nature and is responsible for the behavior of charged particles such as electrons and protons.
3. Strong Nuclear Force: The strong nuclear force is the force that binds together subatomic particles such as protons and neutrons. It is one of the four fundamental forces in nature and is responsible for the stability of atomic nuclei.
4. Weak Nuclear Force: The weak nuclear force is the force that is responsible for certain types of radioactive decay. It is one of the four fundamental forces in nature and is responsible for the decay of certain unstable atomic nuclei.