Qed

QCD is a theory of quark interactions much analogous to QED: the interaction is carried by "gluons" (analogous to photons) which couple to the "color" (analogous to charge) of the quarks.

Source: wiktionary

By the way, these days QED is considered a relatively simple example of a quantum field theory.

Source: wiktionary

QED is the theory that explains how electrically charged particles, like electrons, interact with each other and with particles of light (photons). […] Pretty much everything else – certainly everything you see and feel around you – is explained at the deepest known level by QED. Matter, light, electricity and magnetism – it is all QED.

Source: wiktionary

Finally, there is still plenty of room to employ and apply QED theory for predictive purposes, by proposing new phenomena, especially within the realm of photonics, thereby ensuring QED remains relevant to current and future generations of researchers working in chemical physics.

Source: wiktionary