This article is made up of two main parts. The first part points out two different definitions of cabinet – that is, functional and legal definitions. It also highlights the strong points and the shortcomings of both, proposing at the same time a new definition more suitable for a comparative analysis. In doing this, it puts forward some useful criteria with a view to establishing what a minister actually is, what a cabinet is and how it is made up. The second part provides an overview of the structures of governments in 38 countries, from core to junior ministers, on this basis.