Fortune 100 is a list of the top 100 companies of Fortune 500, which are ranked based on the annual revenue of the companies in a fiscal year. Initially, it included only a few business sectors like manufacturing, mining, and energy. Slowly, it expanded to include banking, healthcare, transport, utilities, insurance, software, etc. In 2021, the top 5 on the Fortune 500 list were Walmart, Amazon, Apple, CVS Health and UnitedHealth Group. Along with Fortune 500, they also release lists like Fortune 100 Best Companies to Work For and the World’s Most Admired Companies, etc., based on various factors like the company’s policy of adapting to changes and employee feedback.