1 Historical Introduction.- 2 Standard Theory of Electroweak Interactions.- 3 Applications of the Electroweak Theory.- 4 Neutrino Sources and Detection.- 5 Properties of the Neutrino.- 6 Massive Neutrinos.- 7 Quantisation of the Majorana Field.- 8 Generation Mixing of Neutrinos.- 9 Models for Massive Neutrinos.- 10 Magnetic Moment of the Neutrino.- 11 Baryon Asymmetry in the Universe and Neutrinos.- Note Added in Proof.- References.