In July 1992, over 300 astronomers attended the Third Tetons Summer School on the subject of "The Environment and Evolution of Galaxies". This book presents 28 papers based on invited review talks and a panel discussion on "The Nature of High Redshift Objects". The major themes include: the interstellar and intergalactic medium, galaxy formation and evolution, cooling flows, quasars and radiation backgrounds, and interactions between galaxies/AGNs and their environment. Recent advances with the ROSAT, COBE and Hubble Space Telescope are discussed, together with current theoretical developments. The tutorial nature of the papers should make this book a useful supplement for professional astonomers, graduate students, and senior undergraduates. As with previous Tetons conferences, this book provides both the current state of observational and theoretical research and material complementary to courses in extragalactic and interstellar astrophysics.