Warren Buffett is the CEO and chairman of Berkshire Hathaway, a large conglomerate company. He has donated over $31 billion to charity and is considered one of the most successful investors of the 20th century. The document provides details about Berkshire Hathaway's financial performance, Buffett's investing philosophy and skills, and his emphasis on patience, value investing, and having the right temperament as an investor. It also discusses Buffett's early business ventures and philanthropic efforts.