This review is devoted to the study of the mechanism of electroweak symmetry breaking and this first part focuses on the Higgs particle of the Standard Model. The fundamental properties of the Higgs boson are reviewed and its decay modes and production mechanisms at hadron colliders and at future lepton colliders are described in detail.;[;[GRAPHICS];The decay branching ratios of the Standard Model Higgs boson and its production cross sections in the main channels at the LHC and at a 500 GeV e+e(-) collider. (C) 2008 Published by Elsevier B.V.