Photons are spin one, and mediate the electromagnetic interaction. They have zero mass and propagate at c. There are actually three types of neutrino (and the

Photons are spin one, and mediate the electromagnetic interaction. They have zero mass and propagate at c. There are actually three types of neutrino (and they spontaneously change from one type to another), they are all spin-one-half, and they interact with other matter only via the weak nuclear force, which has a much smaller effective distance than the electromagnetic force, so they don't interact very often. They have non-zero mass, but it is so small that we don't actually know what it is. Everything in the universe exhibits the wave-particle duality.