The unique capacity, robust vascular supply, and drainage of the liver allow for surgeons to perform formal, nonanatomic, and parenchymal sparing resections for primary and metastatic hepatic lesions. Knowledge of hepatobiliary anatomy is crucial to allow for safe dissection and adequate preservation of the future liver remnant. The functional anatomy of the liver is based on Couinaud classification. Vascular, portal and biliary anatomic variations are necessary to identify on preoperative imaging to avoid unintentional injuries. Conventional common hepatic artery, hepatic arterial branches, portal, and biliary anatomy account for 89%, 55%, 92.5%, and 57%, respectively, of the population.