Interdependence between Microeconomics and Macroeconomics
Macroeconomic theory has a foundation in microeconomic theory and microeconomic theory has a foundation in macroeconomic theory. Microeconomics and macroeconomics are just like the two sides of the same coin.
We cannot analyze individual behavior without the assumption to aggregate. And likewise aggregate cannot be effective unless individual variables are kept under consideration.
Microeconomics is the study of individual parts of the economy whereas macroeconomics is the study of the economy as a whole. But, these two approaches are not competitive but complementary to each other.