Rollnik, H 1975 1975 Martin, F J. Phys. Colloq. C3-99 41 C3 EM interactions Higgs mechanism Weinberg Salam model electromagnetic interactions gauge theories gravity massive quanta strong interactions unification weak interaction 1980 1980 Reviews the present status of weak interaction phenomenology and discusses the basic principles of gauge theories. The author shows how the Higgs mechanism can give massive quanta of interaction. The so- called 'Weinberg-Salam' model, which unifies electromagnetic and weak interactions, is described. Unification with strong interactions and gravity is mentioned. (4 refs). Boudjema, F Zeppenfeld, Dieter C. R. Acad. Sci. Paris 1097-106 3 4 2002 2002 The key concepts of gauge invariance and spontaneous symmetry breaking that helped build the standard model of particle physics are introduced. A short description of radiative corrections that have made the model pass all precision tests, in particular those from LEP, is presented. (32 refs).