The difference between Province and Realm

Province as a noun:

A region of the earth or of a continent; a district or country.

Province as a noun:

An administrative subdivision of certain countries, including Canada and China.

Province as a noun (Roman history):

An area outside Italy which is administered by a Roman governor.

Province as a noun (Christianity):

An area under the jurisdiction of an archbishop, typically comprising a number of adjacent dioceses.

Province as a noun (Roman Catholicism):

An area under the jurisdiction of a provincial within a monastic order.

Province as a noun (in plural, chiefly with definite article):

The parts of a country outside its capital city.

Province as a noun:

An area of activity, responsibility or knowledge; the proper concern of a particular person or concept.

Realm as a noun:

An abstract sphere of influence, real or imagined.

Realm as a noun:

The domain of a certain abstraction.

Realm as a noun (computing):

A scope of operation in networking or security.

Realm as a noun (formal, or, legal):

A territory or state, as ruled by a specific power, especially by a king.

Realm as a noun (fantasy, RPG):

An otherworldly dimension or domain — magical, ethereal, or otherwise — usually in reference to one ruled or created by a mystical character.