In particle physics, a boson (/ ˈ b oʊ z ɒ n / / ˈ b oʊ s ɒ n /) is a subatomic particle whose spin quantum number has an integer value (0, 1, 2,...). Bosons form one of the two fundamental classes of subatomic particle, the other being fermions, which have odd half-integer spin (1 ⁄ 2, 3 ⁄ 2, 5 ⁄ 2,...). Every observed subatomic particle is either a boson or a fermion. Paul Dirac coined the name boson to commemorate the contribution of Satyendra Nath Bose, an Indian physicist.