2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/49597I briefly review some recent progress in the theory of nonleptonic B decays. After introducing the operator product expansion and the relevant effective Hamiltonian, I discuss the domain of validity and the theoretical justification of the factorization approximation and of its generalizations. Furthermore, I review some general parameterizations of B decay amplitudes: the "diagrammatic" approach and the formalism based on Wick contractions in the matrix elements of four-fermion operators.11 pages, 4 figures; invited talk presented at the 8th International Symposium on Heavy Flavour Physics (Heavy Flavours 8), Southampton, UKHigh Energy Physics - Phenomenologytext