A sacrament is a special religious rite in some Christian churches.
The Roman Catholic Church recognizes seven sacraments: Baptism, Confirmation (or Chrismation), the Eucharist, Penance (or Reconciliation), the Anointing of the Sick (or Unction or Healing), Holy Orders and Matrimony. Protestant churches usually recognize only Baptism and the Eucharist (or Holy Communion) as sacraments. The others may be religious ceremonies, but not sacraments.
A Catholic definition of what constitutes a sacrament holds that it must have been ordained by Christ, must forgive sin, must confer Grace, and must utilize physical objects as vehicles for transmitting the spiritual benefits already mentioned. At the time of the Protestant Reformation, Protestant churches held that five of the sacraments recognized by the Roman Catholic Church failed to meet one or more of those four tests established by the Catholic Church itself.
For example, Matrimony was not a new practice at the time of Christ. Then too, Jesus does not appear to have authorized Holy Unction, although the annointing of the sick by church elders is mentioned in the New Testament. The Anglican Church's Articles of Religion contend that the Catholic doctrine of Transubstantiation negates the sacramental character of the Sacrament of Holy Communion because if the bread and wine are rendered non-existent, as is claimed, there is no longer any physical component.
The Orthodox Church accepts the same set of sacraments as the Catholic Church does, but it declines to number the sacraments. The sacraments of the Orthodox Church are more fully described in an essay: Orthodox Mysteries
The only significant Christian Churches that observe no sacraments at all, in the usual sense of the word, are the Friends (Quakers), Salvation Army, and Unitarians. Most Baptists, instead of referring to sacraments, refer to the two ordinances, namely, baptism and the Lord's Supper, and regard those as symbolic acts of obedience.
"A sacrament is a curious thing in that all members of the group fervently believe in its existence while being unable to satisfactorily define it.".
Ambrose Bierce said that "Rome has seven sacraments, but the Protestant churches, being less prosperous, feel that they can afford only two, and these of inferior sanctity. Some of the smaller sects have no sacraments at all — for which mean economy they will indubitable be damned."
- Sacraments in the Roman Catholic Church