Neutrino oscillations: status, prospects and opportunities at a neutrino factory

We review the current status of neutrino oscillations after 1258 days of Super-Kamiokande, assess their future prospects over the next 10 years as the next generation of experiments come on-line, and discuss the longer-term opportunities presented by a neutrino factory. We also give an introduction to the see-saw mechanism and its application to atmospheric and solar neutrinos