GNI in real terms reflects the real purchasing power of the total income earned by residents, which equals GDP in real terms plus changes in terms of trade, and net external factor income in real terms.

Changes in terms of trade refer to the variation in the volume of imports that can be exchanged out of the same volume of exports, due to price movement between imports and exports. Example: If the prices of exports rise faster than the prices of imports, then an increased volume of imports can be purchased out of the receipts generated by the same level of exports. External factor income in real terms is adjusted by implicit price deflator of domestic demand.