 Fermions are particles which have half integer spin (1/2, 3/2, 5/2 and so on), measured in units of Planck's constant and bosons are particles which have integer spin (0, 1, 2 and so on), measured in units of Planck's constant.Examples of fermions are quarks, leptons and baryons.Quantum of fundamental forces such as gravitons, photons, etc.