Why is ISIS called a proto-state?

A proto-state is a political entity which does not represent a thoroughly institutionalized or autonomous sovereign state. A proto-state is also known as a quasi-state. It is a term which meaning fluctuates depending upon the context it is used.

The definition has been confused by the interchangeable use of the terms state, country and nation to describe a given territory. The term proto-state is preferred to "pro-nation." In an academic context, however, since some authorities also use the nation to denote a social, ethnic, or cultural group capable of forming its state.