Definitions for "Parton"
The constituents of protons and neutrons are q uarks, gluons and anti-quarks. They are collectively known as partons.
In particle physics, the parton was a hypothetical fundamental particle considered, in the "parton model" of strong interactions, to be a constituent of the hadron. In the 1970s, quantum chromodynamics showed that hadrons are composed of quarks and gluons, but the parton model is still used to explain some aspects of short-distance interactions.