Preliminaries -- A Brief History of Cosmology and Galaxy Formation -- The Large-Scale Structure of the Universe -- Galaxies -- Clusters of Galaxies -- The Basic Framework -- The Theoretical Framework -- An Introduction to Relativistic Gravity -- The Friedman World Models -- The Robertson-Walker Metric for an Empty Universe -- The Determination of Cosmological Parameters -- The Thermal History of the Universe -- Nucleosynthesis in the Early Universe -- The Development of Primordial Fluctuations Under Gravity -- The Evolution of Perturbations in the Standard Big Bang -- More Tools and Problems -- Dark Matter and Galaxy Formation -- Correlation Functions and the Spectrum of the Initial Fluctuations -- Fluctuations in the Cosmic Microwave Background Radiation -- The Post-Recombination Universe -- The Post-Recombination Era -- The Evolution of Galaxies and Active Galaxies with Cosmic Epoch -- The Intergalactic Medium -- Making Real Galaxies -- The Very Early Universe.