Baryons are a class of particles that include protons and neutrons. They are the heaviest particles in the Standard Model of particle physics, and they play a significant role in nuclear reactions. In addition to their mass, baryons have another property called “baryon number.” This number is conserved in all interactions, and it determines how baryons interact with each other.
Baryons are thought to be made up of quarks, which are the fundamental building blocks of matter. Quarks come in six diverse types, or “flavors”: up, down, strange, charm, bottom, and top. The proton is made up of two up quarks and one down quark; the neutron is made up of one up quark and two down quarks. All other baryons are made up of combinations of these three quarks.
The strong force is what holds the quarks together inside a baryon. This force is mediated by gluons, which are also made up of quarks. The powerful force is responsible for keeping the proton and neutron inside the nucleus of the atom together. It is the strongest known force in nature, but it only works at noticeably short distances (on the order of the size of the nucleus).