<P> 1 Introduction<BR> 1.1 The Hierarchy Problem of Particle Physics<BR> 1.2 The QCD Solution and the Electroweak Puzzle<BR> 2 Effective Theories of Electroweak Interactions<BR> 2.1 Fermi Theory<BR> 2.2 Massive Gauge Bosons<BR> 2.3 The Chiral Lagrangian<BR> 2.4 The Standard Model and Beyond<BR> 3 Scattering Amplitudes of Massive Vector Bosons<BR> 3.1 Goldstone Boson Scattering<BR> 3.2 Resonances<BR> 3.3 Non-Resonant Inelastic Scattering<BR> 4 Collider Signatures<BR> 4.1 Precision Observables<BR> 4.2 $W$ and $Z$ Scattering Amplitudes<BR> 4.3 Lepton Colliders<BR> 4.4 Hadron Colliders<BR> 5 Outlook<BR> References</P>