This document provides an introduction to the concept of cartels in economics. It defines a cartel as a group of firms in the same industry that collude to maximize profits. Cartels are able to earn profits that are 300-3000 times higher than non-cartel firms through raising barriers to entry and controlling prices and competition in their market niche. The document will examine the mathematical structure of cartels and provide two real-world examples of famous cartels, including the Medellin drug cartel and investment banking, to demonstrate how cartels operate.