basic purpose of this article is to Define and Discuss on Gross Domestic Product. Gross Domestic Product or GDP is defined as the market value of final goods and services produced domestically in a single year and is the single most critical measure of macroeconomic efficiency. A related measure in the economy’s total output product is gross national product (GNP), which is the market value of final goods and services made by a nation in a single year. There are two ways of calculating GDP, the expenditure approach and also the income approach. Here briefly discuss on these two types with example.