This chapter provides an overview of the field of neutrino physics, where particular focus is given to the theory and experimental status of neutrino oscillations. The chapter begins with a discussion on the history of neutrino physics from its earliest days. Accounts of this history that are aimed at a general audience can be found in [1, 2]. An overview of the theory of neutrinos interactions in the Standard Model is then followed by a review of the phenomena of neutrino oscillations.