  These lectures review phases and phase transitions of the Standard Model,
with emphasis on those aspects which are amenable to a first principle study.
Model calculations and theoretical ideas of practical applicability are
discussed as well. Contents: 1.Overview; 2. Field Theory at Finite Temperature
and Density; 3.Critical Phenomena; 4.Electroweak Interactions at Finite
Temperature; 5. Thermodynamics of Four Fermions models; 6.The Phases of QCD;
7.QCD at Finite Temperature, $\mu_B = 0$; 8.QCD at Finite Temperature, $\mu_B
\ne 0$.
