Definition - What does Neutrino mean?
Neutrino is an elementary particle which has a half-integer spin and is electrically neutral. It has mass which is very tiny as compared to the mass of other subatomic particles. It is considered to be the one and only candidate for the dark matter categorically the hot dark matter. It is denoted by the letter 'v'. Leptons, together with the charged taus, electrons and muons are the Neutrinos which can be categorized in three flavors – tau neutrinos, electron neutrinos and muon neutrinos which also have a half-integer spin and no electric charge.
Petropedia explains Neutrino
Neutrinos have no electric charge that means that the electromagnetic forces can never affect them. The strong forces acting on particles present inside the nuclei also do not affect them. They are thus affected by the gravitational force and the weak subatomic force. These weak forces have short-range interaction and the gravitational force on the subatomic scale is acutely weak. They can be created in various ways including nuclear reactions taking place in nuclear reactor, the Sun, radioactive decay, supernovas and also when the cosmic rays hit the atoms. They are also being constantly produced from the nuclear bombs and nuclear power stations.