The NUTS regions are defined as below by Eurostat (link):
The Nomenclature of territorial units for statistics, abbreviated NUTS (from the French version Nomenclature des Unités Territoriales Statistiques) is a geographical nomenclature subdividing the economic territory of the European Union (EU) into regions at three different levels (NUTS 1, 2 and 3 respectively, moving from larger to smaller territorial units). Above NUTS 1, there is the 'national' level of the Member States. The NUTS is based on Regulation (EC) No 1059/2003 of the European Parliament and of the Council of 26 May 2003 on the establishment of a common classification of territorial units for statistics (NUTS), which is regularly updated.
- NUTS1: Major socio-economic regions (one NUTS1 area typically contains several NUTS2 areas);
- NUTS2: Basic regions for the application of regional policies (one NUTS2 area typically contains several NUTS3 areas);
- NUTS3: Small regions for specific diagnoses.
In Keep, NUTS0 is used to refer to countries for user convenience, even though the NUTS0 level is not recognized as such by Eurostat.