The term pastor usually refers to an ordained person within a Christian church. In some countries the term is more usually used in traditional Protestant churches but is also used in reference to priests and bishops within the Anglican, Roman Catholic and Orthodox churches.
https://en.wikipedia.org/wiki/Pastor
In Christian churches, a minister is someone who is authorized by a church or religious organization to perform clergy functions such as teaching of beliefs; performing services such as weddings, baptisms or funerals; or otherwise providing spiritual guidance to the community.
https://en.wikipedia.org/wiki/Minister_(Christianity)
Deacon is a role in the Christian Church that is generally associated with service of some kind, but which varies among theological and denominational traditions. In many traditions, the diaconate is a clerical office; in others, it is for laity.
https://en.wikipedia.org/wiki/Deacon
A bishop is an ordained or consecrated member of the Christian clergy who is generally entrusted with a position of authority and oversight. The office of bishop is one of the three ministerial offices within Christianity, the other two being those of priest (presbyter) and deacon.
https://en.wikipedia.org/wiki/Bishop
The Reverend is a style used as a prefix to the names of many Christian clergy and ministers. It is correctly called a style rather than a title or form of address. The style is also sometimes used by leaders in non-Christian religions such as Buddhism.
https://en.wikipedia.org/wiki/Reverend
