canon law, the power to govern the church is divided into the power to make laws (legislative), enforce the laws (executive), and to judge based on the law (judicial).
 A person exercises power to govern either because the person holds an office to which the law grants governing power or because someone with governing power has delegated it to the person. Ordinary power is the former, while the latter is delegated power.
 The office with ordinary power could possess the governing power itself (proper ordinary power) or instead it could have the ordinary power of agency, the inherent power to exercise someone else's power (
vicarious ordinary power).
The law vesting ordinary power could either be ecclesiastical law, i.e. the positive enactments that the church has established for itself, or divine law, i.e. the laws which the church believes were given to it by God.
 As an example of divinely instituted ordinaries,
Catholics in communion with the
Holy See believe that when
Jesus established the Church He also established the
episcopate and the
Primacy of Simon Peter, endowing the offices with power to govern the Church.
 Thus, in the Catholic Church, the office of successor of Simon Peter and the office of diocesan bishop possess their ordinary power even in the absence of positive enactments from the Church.
Many officers possess ordinary power but, due to their lack of ordinary executive power, are not called ordinaries. The best example of this phenomenon is the office of
judicial vicar, a.k.a.
officialis. The judicial vicar only has authority through his office to exercise the diocesan bishop's power to judge cases.
 Though the vicar has vicarious ordinary judicial power, he is not an ordinary because he lacks ordinary executive power. A
vicar general, however, has authority through his office to exercise the diocesan bishop's executive power.
 He is therefore an ordinary because of this vicarious ordinary executive power.