Theory of CP Violation

CP violation in K and B decays is reviewed in the Standard Model (SM) and beyond the SM. In K decays, one is seeking first evidence for CP violation in direct $K\to \pi \pi$ decays. This would not give a precise quantitative test for the present explanation of CP violation in terms of a phase in the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Such tests are provided by a variety of CP asymmetries in neutral and charged B decays. Certain features, characterizing CP violation beyond the standard model, are outlined in the B meson system.