What is a sacrament? A sacrament is an outward sign instituted by Christ to give grace.
How many sacraments are there? There are seven sacraments: Baptism, Confirmation, Holy Eucharist, Penance, Anointing of the Sick, Holy Orders, and Matrimony.
From whom do the sacraments receive their power to give grace? The sacraments receive their power to give grace from God, through the merits of Jesus Christ.
Let a man so account us, as servants of Christ and stewards of the mysteries of God. (I Corinthians 4:1)
Further reading: CCC 1210-1212