Macroeconomics is a branch of economics that studies how an overall economy. It studies the market or other systems that operate on a large scale. It can also be termed as study of their behaviours. Macroeconomics studies phenomenon which are present in the whole economy. This phenomenon includes inflation and national income and gross domestic product and many more. Macroeconomics address some key question of the economics. It gives us the causes of the unemployment and the inflation. It also gives us insights on what creates or stimulates economic growth. Macroeconomics attempts to measure how well an economy is performing. It also attempts to understand what forces drive the economy and to project how performance can be improved. Macroeconomics deals with the entire economy. In contrast the microeconomics is more focused on the choices made by individual actors in the economy. These individual actors might people or households or industries. Macroeconomics focuses on the way the economy performs as a whole and then analyses how different sectors of the economy relate to one another to understand how the aggregate functions. Macroeconomists develop models explaining relationships between these factors. Such macroeconomic models and the forecasts they produce are used by government entities to aid in the construction and evaluation of various policies. Given the enormous scale of government budgets and the impact of economic policy on consumers and businesses macroeconomics clearly concerns itself with significant issues. Economic theories when properly applied can offer illuminating insights on how economies function and the long term consequences of particular policies and decisions. Macroeconomic theory can also help individual businesses and investors make better decisions through a more thorough understanding of the effects of broad economic trends and policies on their own industries. It is also important to understand the limitations of economic theory. Theories are often created in a vacuum and lack certain real world details like taxation and regulation and transaction costs. The real world is also decidedly complicated and includes matters of social preference and conscience that do not lend themselves to mathematical analysis.