A sacrament is a sacred, visible sign that is instituted by Jesus to give us grace.
It is given freely by God; you cannot earn this grace.
There are 7 Sacraments of the Church:
Sacraments of Initiation
Sacraments of Healing
Sacraments of Service
The seven sacraments touch all the stages and all the important moments of Christian life: they give birth and increase, healing and mission to the Christian’s life of faith. There is thus a certain resemblance between the stages of natural life and the stages of the spiritual life.”
(Catechism of the Catholic Church, 1210)