Macroeconomic Theory is a branch of economics that studies the behavior and performance of an economy as a whole. It focuses on aggregate indicators such as GDP, unemployment rates, and inflation to understand how different sectors interact and influence overall economic health. This theory helps policymakers and economists analyze economic trends and make informed decisions. By examining factors like monetary policy and fiscal policy, macroeconomic theory provides insights into how governments can stimulate growth or control inflation, ultimately aiming for a stable and prosperous economy.