  I review promising approaches to neutrino mass models, focussing on three
neutrino patterns of neutrino masses and mixing angles, and the corresponding
Majorana mass matrices. I discuss the see-saw mechanism, and show how it may be
applied in a very natural way to give a neutrino mass hierarchy with large
atmospheric and solar angles by assuming single right-handed neutrino
dominance. A theoretical framework for understanding quark and lepton
(including neutrino) masses and mixing angles based on SUSY, GUTs and Family
symmetry is then described, and sample models which involve single right-handed
neutrino dominance are discussed.
