Matrimony

From a valid marriage arises a bond between the spouses which by its very nature is perpetual and exclusive; furthermore, in a Christian marriage the spouses are strengthened and, as it were, consecrated for the duties and the dignity of their state by a special sacrament. (Catechism of the Catholic Church, 1683)

Resources on the Sacrament of Holy Matrimony:

American Catholic Resources
Marriage: United in Love, Strengthened for Service
The Sacrament of Matrimony
Sacrament of Matrimony Jeopardy Game