  The mechanism extending spontaneous symmetry breaking to gauge fields had a
considerable impact on both theoretical and experimental elementary particle
physics. It is corroborated by the discovery of the Z and the W, and by the
precision electroweak tests. A detection of its Scalar boson(s) would not only
constitute a direct verification of the mechanism, but knowledge of its
couplings to known particles could pave the way to the world hitherto hidden
beyond the Standard Model. These topics are discussed with emphasis on
conceptual issues.
