independent search for new physics.the Standard Model multiplet structure and an analysis in a framework which provides a model constraints on Standard Model parameters and on new particles, the sensitivity to deviations from so far. \Ve present several analyses which reveal specific aspects of the results, such as their of t.hese measurements a.nd their theoretical parametrization and summarize the results available charge asymmetry and of final state radiation in hadronic events. \Ye discuss experimental aspects partial widths and forward-backward asymmetries of heavy quark flavours, of the inclusive q § and leptonic cross sections, leptonic forward-backward asymmetries, T polarization asymmetries, LEP offers a rich choice of tests of the electroweak t.heorv such as the measurement of hadronic provide a window to new physics in an energy domain which is beyond the reach of present or even the with masses far beyond the range of direct production. Their precise measurement might therefore contrast to pure QED. radiative corrections in the electroweak theory are also sensitive to particles at the Z0 resonance can be compared with tests of QED like those of the g -2 experiments. In probe tiny modifications to the tree level processes. The electroweak precision tests in e+e" collisions to extend these tests of the theory to a variety of aspects inherent to its quantum structure and to colliders LEP and SLC The analysis of e+e" collisions at LEP and SLC offers a unique opportunity to establish the theory in considerable detail. well before the start of Z0-pole physics at the e+e" ofthe neutral current in neutrino scattering experiments Since then many experiments contributedThe first experimental success of the Standard Model of electroweak interactions [1] was the discovery