The exponential expansion of knowledge in the field of hepatobiliary diseases makes systematic revisions of current concepts almost mandatory nowadays. This eBook summarizes the progress in understanding the molecular mechanism of cholesterol and bile acid metabolism and the physical-chemistry of biliary lipids, with emphasis on biliary lipid metabolism that is regulated by nuclear receptors in the hepatobiliary system. By guiding the readers through the various aspects of anatomy, physiology, and biochemistry of all ""players"" involved in bile formation, this eBook is intended to be a compendium of recent progresses in understanding the molecular mechanisms of cholesterol and bile acid metabolism.