  The study of electron-positron collisions at LEP, together with additional
measurements from other experiments, in particular those at SLC and at the
Tevatron, has allowed for tests of the electroweak Standard Model with
unprecedented accuracy. We review the results of the electroweak precision
tests and their implications on the determination of the Standard Model
parameters, in particular of the Higgs boson mass, and comment on the
constraints for possible new physics effects.
