  In the inflationary scenario all the matter constituting the universe was
created from the process of reheating after inflation. Recent development of
the theory of reheating is briefly reviewed. The list of topics includes
elementary (perturbative) theory of reheating; quantum field theory in a
time-varying background; parametric resonance and explosive particle creation;
non-thermal phase transitions from reheating; baryogenesis from reheating;
residual oscillations of the scalar field, and other cosmological applications.
