A sacrament is a rite or ceremony instituted by Jesus, and observed by the church as a means of or visible sign of grace. As a visual aid, it illustrates and confirms the spiritual truths and promises contained in the gospel.
The English word sacrament is from the Latin sacramentum, which means to make holy, or to consecrate.
Sacraments are ceremonial in nature, which separates them from other things that Jesus instructed believers to do (for example, "go and make disciples of all nations", Matthew 28:18).
The Presbyterian Church in Ireland celebrates two sacraments, Baptism and Communion.