To measure a nation’s economic performance and activity from a very broad sense(= in general), experts usually look at their gross domestic product (GDP).
Essentially, GDP refers to the total monetary value(=price) of all the completed goods and services that have been produced within a country’s borders in a set period of time.
Looking at the overall productivity of a country acts as a quick but effective measure of their economic health; it’s easily comparable against their previous reports, and, against other countries in previously similar economic positions.
Typically calculated on an annual basis(= every year), GDP can also be carried on a quarterly or even monthly basis to give a more specific picture of a given time period. For example, the UK publishes its GDP estimates on a monthly and quarterly basis(=every 3 months) to give a more accurate breakdown(=explanation) and short-term indication of the economy(= the analysis of indicators in comparison with a fixed reference year).