What is a relic? A relic is the body, a part of the body, or some personal memorial of a saint preserved as worthy of veneration. A reliquary is a container for relics.

First-Class Relic: physical remains of a saint (e.g. bone, hair).

Second-Class Relic: personal effects of a saint, something they owned or frequently used (e.g. clothing, book, rosary).

Third-Class Relic: object that has touched a first-class relic. 

Relics are explicitly biblical:

• So Elisha died, and they buried him. Now bands of Moabites used to invade the land in the spring of the year. And as a man was being buried, lo, a marauding band was seen and the man was cast into the grave of Elisha; and as soon as the man touched the bones of Elisha, he revived, and stood on his feet. (2 Kings 13:20-21)

• And God did extraordinary miracles by the hands of Paul, so that handkerchiefs or aprons were carried away from his body to the sick, and diseases left them and the evil spirits came out of them. (Acts 19:11-12)

Learn more: Catholic Answers; National Catholic Register; Ascension Press

A shrine is a church or other sacred place where either a relic is preserved or where an apparition or historical event of faith has taken place.

A shrine is typically designated to help foster devotion to a particular saint. The Basilica of the National Shrine of the Little Flower (a basilica and a shrine) was built to foster devotion to Our Lady of Mount Carmel and St. Thérèse.

National shrines are designated as such by the United States Conference of Catholic Bishops (USCCB).

The Carmelite Order has its origins on Mount Carmel in the Holy Land with the coming together of a group of hermits in the early 13th Century, forming the first religious order in the West to be named for the Virgin Mary - the Brothers of the Blessed Virgin Mary of Mount Carmel. The reform of the Order by St. Teresa of Jesus (commonly known as St. Teresa of Avila) undertook to provide the Church with a manifold service of prayer, contemplation, and apos­tolic activity. The Discalced Carmelite Friars, Nuns, and Seculars continue this contemplative mission today, seeking union with God and sharing their charism and spirituality with the Church and the world.

Learn more about the Discalced Carmelites and their vocation here.