The labels, "type I" and "type II," of different kinds of supernova come from observational astronomy and reflect a fundamental difference in their observed spectrum. What is that difference and, for type Ia and type II supernovae, how is it related to the evolution that leads to the supernova explosion? Why are type Ia supernovae so important to distance measurement in astronomy? What are the possible remnants of a type II supernova? Where and in what process were all the heavy metals and rare-earth elements, like gold, created?