Wikipedia defines GDP as:
Measure of the market value of all final goods and services produced in a period (quarterly or yearly) of time.
So, I take it that the total value of all goods (and services, whatever "Services" means) manufactured within the country per year is the country's GDP. This YouTube video does a nice job of explaining it too:
The United States GDP, also from Wikipedia, is around $19 trillion!
According to the definition, US should manufacture USD 19 trillion worth of goods (finished products) and services within the US, but again, according to this Wikipedia article, US manufacturing industry outputs only about $2.2 trillion worth of goods.
So, what accounts for the remaining $17 trillion? Is it the "Services"? If so, what are these services and how are they measured?