What are the different types of galaxies? What hints can they give us as to the structure and evolution of galaxies? This lecture introduces the Hubble Classification System for galaxies, and describes the properties of each major class. This detailed overview gives us some tantalizing clues as to the formation and evolution of galaxies that will be picked up in subsequent lectures. Recorded 2006 February 13 in 1008 Evans Laboratory on the Columbus campus of The Ohio State University.