The gross national product, or GDP, measures the nation's total economic activity. It is pretty much the value of all goods and services in a economy. GDP is very important because it is one of the ways to see how a economy is functioning, and to see if the country is doing good or not. If a countries GDP is always going up, they're doing really good, but if a country has its GDP going down, then the company is not doing so well on making profit. If a economies GDP goes down, that's profit they're losing, and if it keeps going down, the economy could go broke. What GDP calculates is the products that the country makes, which is profit towards the country, but GDP does not include any products that are made by foreign companies.