Leptons

Leptons are elementary particles in the standard model, meaning they have no apparent further internal structure. The family of leptons includes electrons, muons, tau-lepton, a neutrino associated with each of these, and the set of anti-particle equivalents (but there is some fuzziness about antineutrinos... don't ask). They are named after the fractional parts of Greek currency from way-back-when. Technically, they have baryon number 0, unity electrical charge (+1, 0, or -1 e),  and zero colour charge. Leptons are involved in all types of physical interactions except the strong nuclear force.