Caption: Besides what it obviously illustrates, the diagram illustrates the usages of the word "fundamental" in physics.
Features:
The standard model of particle physics unites the electromagnetic force, the strong nuclear force, and the weak nuclear force. Gravitation has NOT yet been united with the other fundamental forces.
The hypothetical theory of everything (TOE) (for which we have NO established theory, but just a name) is supposed to give that complete unification of the forces among other things. The complete unification would give the singular most fundamental fundamental force.