: The book focuses on transitioning into the B (Business) and I (Investor) quadrants. E (Employee) : Trades time for money.

"The Business of the 21st Century" is a book written by Robert Kiyosaki, a well-known entrepreneur, investor, and author of the best-selling book "Rich Dad Poor Dad." The book was first published in 2010 and has since become a classic in the field of personal finance and entrepreneurship. The book's central theme is that the traditional 9-to-5 job is no longer a secure or reliable way to achieve financial stability and that individuals must take control of their financial lives by starting their own businesses.

There are four types of income: