All visible matter in the universe is made from the first generation of matter particles: up quarks, down quarks and electrons.
Quarks are very social and exist only in groups (hadrons) with other quarks.
Meson = 1 quark + 1 antiquark + 1 gluons
(For every particle/matter there is a corresponding antiparticle/antimatter).
Baryon = any group of 3 quarks + gluons
For example:
- Proton = 2 up quarks + 1 down quark
- Neutron = 1 up quark + 2 down quarks
