  These notes are based on five lectures presented at the 2004 Theoretical
Advanced Study Institute (TASI) on ``Physics in D>=4''. After a brief
motivation of flavor physics, they provide a pedagogical introduction to
effective field theory, the effective weak Lagrangian, and the technology of
renormalization-group improved perturbation theory. These general methods are
then applied in the context of heavy-quarks physics, introducing the concepts
of heavy-quark and soft-collinear effective theory.
