The definition of exorcism, courtesy of the Catholic Encyclopedia, is "the act of warding off or driving out demons or evil spirits from persons, places, or things that are believed to b possessed or infested by them, or are liable to become victims or instruments of their malice". In other words, an exorcism is basically a ritual performed by a priest to drive a demon or devil out of a person, place, or thing.

There are several different types of exorcism used in the Roman Catholic Church. These types of warding off demons are: a simple exorcism a baptismal exorcism a real exorcism.

A simple exorcism is just that. It is when a priest blesses a place or thing in order to ward off evil influences, like demons. A baptismal exorcism consists of babies being blessed by a priest prior to being baptized. This is done to cleanse them of demons and evil that can come about from original sin. Finally, a real exorcism is the act we think of most. It is the act of ridding a human being of demons that possess them.

Roman Catholics are not the only religion that deal with exorcism. Many religions and cultures have their own way of casting out and warding off demons. A few examples include: Judaism, Islam, Hinduism.

While different religions or cultures may have a different name for their demons, basically, all of the names boil down to the same meaning. A demon, in any religion or culture, will try to possess a person, place, or thing with the intent of no good. How these demons are expelled from the person, place, or thing, may be quite different in different religions and cultures. For example, while a Hindu exorcism can involve rituals like burning cow dung, a Islam exorcism can involve reciting certain passages from the Qur'an.