What is the difference between a church, a cathedral, and a basilica?

A church is a building dedicated to Christian worship. A cathedral is the principal church of a diocese, while a basilica is a church given a special title by the pope.

What a church is. In this context, a church is a sacred building set apart for divine worship and open to the faithful (Canon 1214). Churches are normally dedicated or blessed according to the Church's liturgical rites (Canon 1217). They contain an altar for the Eucharistic sacrifice, a place for proclaiming God's Word, and ordinarily a tabernacle for reserving the Blessed Sacrament. A Catholic church is both a house of prayer and a visible sign that God dwells among His people in Christ (CCC 1180-1181).

The word "Church" can also mean the People of God or the universal Catholic Church, rather than a building. The context usually makes the meaning clear. A parish church is the principal place of worship for a local parish community under the care of its pastor.

What a cathedral is. A cathedral is the church containing the bishop's cathedra, his official chair. The chair symbolizes his teaching and governing authority as successor of the apostles. Because the bishop leads a diocese, the cathedral serves as the diocese's principal church and the center of its liturgical life. Major diocesan celebrations, such as ordinations and the Chrism Mass, are commonly held there. A large or impressive church is not necessarily a cathedral. Its status comes from its relationship to the diocesan bishop.

What a basilica is. A basilica is a church that has received an honorary designation from the pope because of its historical, liturgical, or spiritual importance. The four major basilicas are in Rome: St. John Lateran, St. Peter's, St. Paul Outside the Walls, and St. Mary Major. Other designated churches throughout the world are called minor basilicas. They have particular responsibilities for worthy liturgical celebration and for fostering communion with the pope.

The title does not depend mainly on size or architectural style. An ancient, modest church can be a basilica, while a much larger building may not be one. The norms governing minor basilicas are set by the Holy See.

How the titles overlap. One building can fit more than one category. Every cathedral and basilica is a church. A cathedral can also be a basilica, as happens in some dioceses. A basilica does not automatically become a cathedral, and a cathedral does not automatically receive basilica status. When visiting any Catholic church, look first for the tabernacle and acknowledge Christ's Eucharistic presence with a genuflection when appropriate.