What is a sacrament in christianity? and explain what each one is?

Baptism, the first and fundamental sacrament and the gate to the other sacraments, is the purifying and sanctifying sacrament of rebirth. It is the means by which its recipients are incorporated into the church in a sacramental bond of unity.

By a signing with the gift of the Spirit, confirmation enriches the baptized with the Holy Spirit, binding them more perfectly to the Church, and strengthening them in their witness to Christ by word and deed and in their work to bring to its fullness the Body of Christ. Confirmation is conferred through anointing with chrism and the laying on of hands.

The Eucharist is the most august sacrament, in which Christ himself is contained, offered and received, and by which the Church constantly lives and grows. The Eucharistic Sacrifice, the memorial of the death and resurrection of the Lord, in which the sacrifice of the cross is perpetuated over the centuries, is the summit and source of all Christian life and worship; it signifies and effects the unity of the people of God and achieves the building up of the Body of Christ.

As children reach the age of reason, generally around age seven, the Church extends to them an invitation to celebrate the sacrament of Eucharist. The initiation into the Christian community that took place at baptism is further extended by inviting children to enter fully into the heart of Christian faith through participation in the Eucharist.

Through penance, the faithful receive pardon through God's mercy for the sins they have committed. At the same time, they are reconciled with the Church community. The confession, or disclosure, of sins frees us and facilitates our reconciliation with others.

Through the sacrament of anointing, Christ strengthens the faithful who are afflicted by illness, providing them with the strongest means of support. Jesus showed great concern for the bodily and spiritual welfare of the sick and commanded his followers to do the same. The celebration of this sacrament is an opportunity for the deepening of the faith of the community who are able to witness the faith and devotion of those being anointed.

The Church has a rich tradition in its teaching on sacramental marriage and covenantal union. The Old Testament authors write of God making a covenant with the chosen people and promising them that they will never be forsaken. The New Testament authors write of Jesus as the new covenant and compare the relationship of Jesus with the Church to the relationship of a husband and wife. The matrimonial covenant, by which a man and a woman establish between themselves a partnership for the whole of life, is by its nature ordered toward the good of the spouses and the procreation and education of offspring.

Holy Orders is the sacrament by which bishops, priests and deacons are ordained and receive the power and grace to perform their sacred duties. The sacred rite by which orders are conferred is called ordination. The apostles were ordained by Jesus at the Last Supper so that others could share in his priesthood.