Relativistic heavy-ion physics: three lectures

These lectures provide an introduction to the physics issues which are being studied in the collisions of ultrarelativistic heavy ions. The lectures are focused on the production of new states of matter. The quark-gluon plasma is thermal matter which once existed in the Big Bang. The colour glass condensate is a universal form of high energy density gluonic matter which is part of a hadron wavefunction and which controls the high-energy limit of strong interactions. The glasma is matter produced in the collisons of high-energy hadrons which evolves into a quarkgluon plasma. The glasma has interesting topological properties and may be responsible for the early thermalization seen at RHIC. I introduce the student to these topics, discuss results from experiments, and comment upon future opportunities.