Heavy Quark Masses, Mixing Angles, and Spin-Flavour Symmetry

In a series of three lectures, I review the theory and phenomenology of heavy quark masses and mixing angles and the status of their determination. In addition, I give an introduction to heavy quark symmetry, with the main emphasis on the development of heavy quark effective field theory and its application to obtain a model-independent determination of $\mathrm{\mid }{V}_{cb}\mathrm{\mid }$.