1. Strong Force: This force binds quarks together to form protons and neutrons, and holds protons and neutrons together in the nucleus of an atom. It's the strongest force, but it only operates over extremely short distances.

2. Electromagnetic Force: This force governs the interactions between electrically charged particles. It's responsible for phenomena like electricity, magnetism, and light.

3. Weak Force: This force is responsible for radioactive decay and is involved in the fusion of atoms in stars. It's much weaker than the strong force and operates over even shorter distances.

4. Gravitational Force: This force is the weakest of the four but has an infinite range. It attracts all objects with mass towards each other and governs the motion of planets, stars, and galaxies.

These four forces are thought to be the fundamental building blocks of the universe, and they explain all known physical phenomena.