Provinces and Dioceses Explained

A province contains one archdiocese and at least one diocese. An archdiocese, also called a metropolitan diocese, is the diocese in a province of which the largest city of the province is within. A diocese, also called a suffragan diocese, is any diocese within a province other than the archdiocese.

E.g., the ecclesiastical province of San Antonio contains the diocese of San Angelo, etc., and the archdiocese of San Antonio.

Dioceses and Provinces Map in the United States: https://en.m.wikipedia.org/wiki/File:US_Roman_Catholic_dioceses_map.png