In Catholic theology a place of cleansing after the particular judgment. After death, persons who repented of their sins but had not expiated them in life are purged before entering heaven. Because everyone who enters purgatory will evenutally reach heaven, it is not a place of punishment and is not related to hell. Prayers for the dead or indulgences can shorten one's own or loved one's stays therein.
The Eastern Orthodox church does not have an official doctrine regarding purgatory per se; however, they do traditionally offer prayers for the dead, asking God to show them his mercy and lovingkindness. Theosis, the process of becoming more like God and more united with God, can begin in this life and can continue after death.
Protestant churches generally reject the belief in purgatory. Catholics quote II Maccabees 12:45 in defence; but Protestant do not recognise that book as canonical as it is in a group of books called by Protestants the Apocrypha and by Catholics and Orthodox the Deuterocanonical Books.