What is a Gluon?
Gluons are force-mediating particles that exist in every atomic nucleus, holding it together. They mediate the strong nuclear force, which is the strongest of nature’s four forces, 137 times stronger than electromagnetism and about 1.6 x 1039 times stronger than gravity, the weakest force. Its limitation is that it only operates on extremely small distances, the scale of the atomic nucleus. At distances longer than one femtometer (width of a medium-sized atomic nucleus) the strong force begins to fade. The strong force holds together all known matter in the universe except for dark matter, which we know practically nothing about. So the atomic nucleus consists of a combination of nucleons (protons and neutrons) and gluons. Like a photon (light), a gluon has no mass. It just represents a packet of force. Unlike photons however, gluons have their own “color” — the name for charge in the strong force — which means they interact with themselves, making quantum chromodynamics (strong force)
” In particle physics, gluons are vector gauge bosons that mediate strong color charge interactions of quarks in quantum chromodynamics (QCD). Unlike the neutral photon of quantum electrodynamics (QED), gluons themselves participate in strong interactions. The gluon has the ability to do this as it itself carries the color charge and so interacts with itself.”  The gluon, as its name suggests, is yet another of those discrete bosons, but for unexplained reasons acts as the glue that holds the nucleus of the atom together. The gluon is a particle that the mathematicians found necessary to justify why the nucleus of an atom doesn’t spontaneously explode. You have to give them a little credit, though. Despite their clumsy ways, the mathematicians eventually figured out that their particle theory ‘predicted’ that two positive protons should repel each other. [Uh Duh!] So then, why doesn’t the atomic nucleus explode? Ergo, there must be yet another secret culprit lurking in the shadows