Most of phenomenologically acceptable supersymmetric models imply breaking of supersymmetry in a separate sector of fields introduced just for this purpose. Supersymmetry breaking is transferred to the Standard Model due to a certain interaction with this additional sector. In this review we discuss one of the popular mechanisms of such mediation with the key role played by the Standard Model gauge interactions. We consider general principles of gauge mediation and give a critical analysis of specific models together with their phenomenological and cosmological implications. We also present basic facts concerning mechanisms of dynamical supersymmetry breaking.