We review recent results on QCD at finite temperature and non-vanishing
baryon number density. We focus on observables which are of immediate interest
to experimental searches for the Quark Gluon Plasma, i.e. the phase transition
temperature, the equation of state in two and three flavour QCD and thermal
effects on hadron masses. Some new developments in finite density QCD are also
presented.Comment: LATTICE99(plenary) 10 pages, LaTeX2e, uses espcrc2.st