Warren Buffett is an American business magnate, investor, and philanthropist. He is the chairman and CEO of Berkshire Hathaway, and has consistently ranked among the world's wealthiest people, becoming the richest person in the world in 2008. Buffett is called the "Oracle of Omaha" and began his career in business at a young age, purchasing stocks starting at age 11. He has built large holdings in companies like Coca-Cola and McDonald's through his investments and has donated billions to charitable causes through his foundation.