"Gross Domestic Product (Gross Domestic Product, referred to as GDP) refers to the total value of final products and services produced by all enterprises, institutions and residents within a certain period of time within a country or region. One of the main indicators of regional economic aggregate.

There are usually three methods used to calculate GDP, namely the output value method, the expenditure method and the income method. The output value method calculates GDP based on the market value of the final products produced by various industries. The expenditure method calculates GDP based on final demand, including personal consumption, government expenditure, investment and net exports. The income method calculates GDP based on the income of factors of production. , including wages, profits, rents, and indirect taxes.

GDP is not only the main indicator of a country or region's economic aggregate, but also plays an important role in many other aspects. First of all, GDP can be used as an important indicator to evaluate the economic development level of a country or region. Secondly, GDP can also be used as an important basis for the government to formulate macroeconomic policies. For example, the government can increase employment and improve social welfare by stimulating economic growth. In addition, GDP can also be used as an important basis for international comparison, comparing the economic scale and development level of different countries or regions.

However, GDP also has some limitations. For example, it fails to capture the output of non-market economies such as housework, subsistence production and illegal economic activities. In addition, GDP cannot reflect the fairness and sustainability of the economy.

In short, GDP is the main indicator of a country or region's economic aggregate, and it plays an important role in evaluating economic development, formulating economic policies, and making international comparisons. However, it also has certain limitations and needs to be continuously improved and improved in practice. "