2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/57898We provide a short introduction to the main features of the algebraic approach to quantum field theories.21 pages, to appear on Elsevier Encyclopedia of Mathematical Physics. We followed the instructions of the publisher for referencing. Comments and/or corrections are welcomeMathematical PhysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theory81T05, 81T20text