Learner's definition of PROVINCE
any one of the large parts that some countries are divided into
a subject or area of interest that a person knows about or is involved in
— usually singular
It's a legal question that is/falls outside my province. [=it does not relate to the area that I know about]
That subject is the special province of this magazine.
Study in that area had once been the exclusive/sole province of academics.
the parts of a country that are away from large cities