Baryons can be contrasted with:
- mesons, which have an even number of elementary particles. The name meson comes from "medium" since their most common examples have two quarks rather than three as the most common baryons such as protons. So they have less mass than a proton, but more than an electron, this medium mass.
- leptons, which are much lighter particles such as the electron. "Leptos" means "fine, small, thin".