The Fortune 500 is an annual list published by Fortune magazine that ranks the 500 largest U.S. companies by total revenue. This list includes both publicly traded and privately held companies, providing a snapshot of the American economy and its leading businesses. The rankings are based on the companies' fiscal year revenues, and the list is widely regarded as a benchmark for corporate success. Companies on the list span various industries, including technology, healthcare, and retail, showcasing the diversity of the U.S. business landscape.