In these lectures I review what has been learned from studies of b-quark decays, including semileptonic decays (V ub and V cb ), B o −B o mixing and rare B decays. Then a discussion on CP violation follows, which leads to a summary of plans for future experiments and what is expected to be learned from them.In higher order other terms have an imaginary part; in particular the V cd term becomes −λ − A 2 λ 5 (ρ + iη), which is important for CP violation in K o L decay.