The flavor sector is that part of the Standard Model which arises from the interplay of quark weak gauge couplings and quark-Higgs couplings. The matrix of quark weak couplings (in the mass eigenstate basis) encodes these effects in four parameters, one of which is a CP violating phase. From a theorist's perspective, the aim of the game in flavor physics today is to search for Standard Model predictions that cleanly relate measurements to these parameters. Such relationships always have some theoretical uncertainty, a clean relationship is one where that uncertainty is well-defined and small. B physics provides multiple channels that can be used to measure various combinations of Standard Model parameters.