A state church is a state religion created by a state for use exclusively by that state. An example of a state religion that's not a state church is Roman Catholicism in Costa Rica which was accepted as the state religion in the 1949 Constitution, despite the lack of a national church. In the case of a state church, the state has absolute control over the church, but in the case of a state religion, the church is ruled by an exterior body (in the case of Catholicism, the Vatican has control over the church).