Typically the government claims to rule on behalf of God or a higher power, as specified by the religion in question.
There are different forms of theocracy. The most classical one is caesaro-papism[?], in which power is shared between a secular ruler (eg an emperor) and a religious leader (eg a pope). Theocracy can also be exercised directly by the clergy (eg Iran) or indirectly (see the divine right of kings).
See also: Oligarchy, democracy, Monarchy, Constitutional monarchy, Islamic republic
wikipedia.org dumped 2003-03-17 with terodump