2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/188471This review summarizes Effective Field Theory techniques, which are the modern theoretical tools for exploiting the existence of hierarchies of scale in a physical problem. The general theoretical framework is described, and explicitly evaluated for a simple model. Power-counting results are illustrated for a few cases of practical interest, and several applications to Quantum Electrodynamics are described.Review article prepared for Annual Reviews of Nuclear and Particle Science, LaTex, 55 pages; new references addedHigh Energy Physics - TheoryAstrophysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Phenomenologytext