This two-volume set provides an accessible, practical, and comprehensive introduction to the gauge theories of the standard model of particle physics. For each, the authors provide a thorough discussion of the main conceptual points, a detailed exposition of many practical calculations of physical quantities, and a comparison of these quantitative predictions with experimental results. The third edition has been expanded and revised to reflect the many developments in the field over the last decade, both in university curricula and in particle physics research. Volume 1, From Relativistic Quantum Mechanics to QED introduces the three gauge theories of the standard model of particle physics: quantum electrodynamics (QED), quantum chromodynamics (QCD), and the electroweak theory. This edition includes new introductory chapters, expanded treatment of relativistic quantum mechanics, and a self-contained introduction to quantum field dynamics as described by Feynman graphs. Volume 2, QCD and the Electroweak Theory: A Practical Introduction introduces the remaining two gauge theories of the standard model. In this edition, simple ideas of group theory are incorporated into the discussion of non-Abelian symmetries. New chapters explore renormalization group and scaling violations in deep inelastic scattering and non-perturbative aspects of QCD using the lattice (path-integral) formulation of quantum field theory.