The liver is a vital organ of the body. It is involved in many essential processes, including digestion, metabolism, immunity, and the storage of nutrients within the body. Any disease affecting the liver affects the entire body. The liver also has the capacity to regenerate. This process takes place by compensatory hyperplasia of mature hepatocytes and nonparenchymal cells, but the liver also possesses hepatic stem/progenitor cells. Knowing the basic pathology of major liver diseases is critical in our understanding of the novel therapeutic techniques being used and studied in regenerative medicine.