Microeconomics is generally the study of individuals and business decisions. Macroeconomics looks at higher up country and government decisions.
Macroeconomics and microeconomics, and their wide array of underlying concepts, have been the subject of a great deal of writings. The field of study is vast; here is a brief summary of what each covers:
Microeconomics
Microeconomics is the study of decisions that people and businesses make regarding the allocation of resources and prices of goods and services. This means also taking into account taxes and regulations created by governments. Microeconomics focuses on supply and demand and other forces that determine the price levels seen in the economy. For example, microeconomics would look at how a specific company could maximize its production and capacity so it could lower prices and better compete in its industry. (Find out more about microeconomics in How does government policy impact microeconomics?
Microeconomics' rules flow from a set of compatible laws and theorems, rather than beginning with empirical study.
Macroeconomics
Macroeconomics, on the other hand, is the field of economics that studies the behavior of the economy as a whole and not just on specific companies, but entire industries and economies. This looks at economy-wide phenomena, such as Gross Domestic Product (GDP) and how it is affected by changes in unemployment, national income, rate of growth, and price levels. For example, macroeconomics would look at how an increase/decrease in net exports would affect a nation's capital account or how GDP would be affected by unemployment rate. (To keep reading on this subject, see Macroeconomic Analysis.)