An exorcism is a religious rite that is quite ancient and part of the belief system of many religions. Performed when someone is believed to be possessed by an evil spirit. The person performing the exorcism, known as an exorcist, is often a member of the clergy, or an individual thought to be graced with special powers or skills.
The exorcist may use prayers, and religious material, such as set formulas, gestures, symbols, icons, amulets, etc.. The exorcist invokes God, Jesus or several different angels and archangels to intervene with the exorcism.
In general, possessed persons are not regarded as evil in themselves, nor wholly responsible for their actions. Therefore practitioners regard exorcism more as a cure than as a punishment. The mainstream rituals usually take this into account, making sure that there is no violence to the possessed, only that they be restrained if there is potential for violence.