What is a Sacrament?

All sacraments are an encounter with Jesus Christ, who is himself the original sacrament. 

The sacraments of initiation, which introduce the recipient into the faith, are: Baptism, Confirmation, and Eucharist.The sacraments of healing are: Reconciliation and the Anointing of the Sick. The sacraments of communion and mission are: Matrimony and Holy Orders.

(Youth Catechism of the Catholic Church, 193)

There are sacraments of Initiation, which introduce the recipient into the faith:

BaptismConfirmation and Eucharist.

There are sacraments of healing:

Reconciliation and the Anointing of the Sick.

And there are sacraments of communion and mission:

Matrimony and Holy Orders. (You Cat # 193)

For more information see:

Catechism of the Catholic Church – Section Two – The Seven Sacraments of the Church #1210 – 1666