  We review different avenues of electroweak symmetry breaking explored over
the years. This constitutes a timely exercise as the world's largest and the
highest energy particle accelerator, namely, the Large Hadron Collider (LHC) at
CERN near Geneva, has started running whose primary mission is to find the
Higgs or some phenomena that mimic the effects of the Higgs, i.e. to unravel
the mysteries of electroweak phase transition. In the beginning, we discuss the
Standard Model Higgs mechanism. After that we review the Higgs sector of the
Minimal Supersymmetric Standard Model. Then we take up three relatively recent
ideas: Little Higgs, Gauge-Higgs Unification, and Higgsless scenarios. For the
latter three cases, we first present the basic ideas and restrict our
illustration to some instructive toy models to provide an intuitive feel of the
underlying dynamics, and then discuss, for each of the three cases, how more
realistic scenarios are constructed and how to decipher their experimental
signatures. Wherever possible, we provide enough pedagogical details, which the
beginners might find useful.
