Tells a lot about a countries state of economic development. Tradition devision in:

 

·      Agricultural

·      Industrial

·      Service

 

We assume that the agricultural sector is biggest in third world, the industrial sector is very dominant in the BRICS, South Eastern Tiger Economies etc, while in the Western world, the service sector is prevalent.
Data confirms.

 

OECD country data:

 

https://www.bls.gov/fls/flscomparelf/lfcompendium.pdf
(p. 7)

 

Databases: World Bank, Bureau of Labor Statistics, OECD