The National accounts are central to the economic policy-making. GDP is one of the key sizes, and it expresses the value of the country's total production and thus what is available to use for private consumption, public consumption, investment and net exports.
The development of GDP describes economic growth, i.e. whether we become richer or poorer. The national accounts have many other important indicators, such as household savings. The national accounts are compiled according to international guidelines (ESA2010), making it comparable between countries.
The national accounts describe the economic cycle. The framework is a consistent and balanced system of economic operations and definitions that show how production activity (when we go to work) generates income which is then distributed (e.g. as wages) and redistributed (e.g. as taxes) before it creates a basis for the demand for goods and services for private consumption and savings. The system also shows how savings are placed (e.g. as a bank deposit).