Gross domestic product is defined by the Organisation for Economic Co-operation and Development (OECD) as
"an aggregate measure of production equal to the sum of the gross values added of all resident and
institutional units engaged in production
(plus any taxes, and minus any subsidies, on products not included in the value of their outputs.")
More simply, it can be defined as a monetary measure of the market value of final goods produced over a period of time,
typically quarterly or yearly,
that is often used to determine the economic performance of a region or country.