In particle physics, a spinor field of order 2s describes a particle of spin s, where s is an integer or half-integer. Therefore, a spinor of order 2s contains as much information as a tensor of order s. As a result of this, particles of integer spin (bosons) can be described equally well by tensor fields or spinor fields, whereas particles of half-integer spin (fermions) can be described only by spinor fields. Spinor fields describing particles of zero rest mass satisfy the so-called zero rest mass equation. Examples of zero rest mass particles include the gauge bosons (as long as gauge symmetry is not violated) such as the photon and possibly one of the neutrinos (a fermion).