This document discusses non-alcoholic fatty liver disease (NAFLD), which includes non-alcoholic fatty liver (over 5-10% fat content) and non-alcoholic steatohepatitis (fatty liver with inflammation, cell injury, and/or fibrosis). It defines NAFLD, examines its epidemiology and etiological factors. It also explores the disease's pathophysiology, diagnosis, and treatment, drawing information from multiple sources on these topics.