The four forces are described in "The Theory of Everything":
The quantum theory describing the electromagnetic force is Quantum Electrodynamics (QED).
The electromagnetic force gathers atoms into a whole, dominates the structure of atoms, and describes how atoms interact with light.
The quantum theory describing the strong force is Quantum Chromodynamics (QCD).
The strong force gathers atomic nuclei into a whole and dominates the structure of atomic nuclei.
Gravity is described by Einstein's General Theory of Relativity.
The gravitational interaction between fundamental particles is very weak, but when a large number of particles gather together, the effect of gravity accumulates and begins to dominate the interactions between large objects.
Weak force
The weak force dominates transformation processes, causing some originally stable particles to decay, such as certain radioactive phenomena, thus initiating an energy-releasing interaction that provides energy for stars, including the sun.