Microeconomics and macroeconomics are the two main categories of economic theory. Microeconomics deals with individual economic units like households and firms, and studies topics like supply and demand. Macroeconomics looks at the overall economy, analyzing issues like GDP, unemployment, and inflation. The key differences are that microeconomics focuses on small economic decisions and market equilibrium, while macroeconomics examines whole economies and factors like interest rates, unemployment, and fiscal/monetary policy. Both branches help explain economic behavior and guide policymaking, but they operate at different levels of analysis.