Economics is present in our lives every day, because every day we check our wallet and pay for something for someone. This is everyday, practical economics. But there is also economics as a science, where researchers use mathematical formulas and statistical methods to analyze economic laws. Over the years, certain rules have been developed in this science, and knowing them can help you avoid mistakes that others have already made. What determines demand and what controls supply? How is trade structured, and how do you learn to trade correctly? How can you increase income and reduce spending? How does the money system work? Why did banks appear? What is the history of money? Answers to these and other questions you will find in this book.