Microeconomics studies individual economic decision-making units like consumers, firms, and industries, while macroeconomics analyzes the economy as a whole in terms of aggregate supply and demand. The key difference is that microeconomics focuses on micro-level variables and macroeconomics focuses on macro-level or economy-wide variables. Microeconomics tools include supply and demand analysis and factor pricing, while macroeconomics tools include analyzing GDP, inflation, unemployment, and other indicators of overall economic performance. Both are important areas of economics that provide insights, though each operates at different levels of analysis.