Macro-economics is concerned with aggregate and averages of the entire economy. Such as national income, aggregate output, total employment, total consumption, saving and investment, aggregate demand, aggregate supply, general level of prices, etc.
In other words, in micro-economics, we study how these aggregates and averages of the economy as a whole are determined and what causes fluctuations in them.
Macro-economics deals also with how an economy grows. In other words, it analyses the chief determinants of economics development and various stages and processes of economics growth.
This part of economics theory has been largely developed in the last two-three decades.