The Roman Catholic Church knows seven such sacraments. These are
Following Martin Luther's tradition, many Protestant churches see only Baptism and Lord's Supper as Sacraments. They also have most of the other rites, but do not consider them to be sacraments.
Eastern Orthodox and Oriental Orthodox Churches basically have the same views as the Roman Catholic Church. They say however, that many things the church does (as church), can be seen as sacraments, in some way.