A cassock is a long, flowing robe that is traditionally worn by members of the clergy in Christian churches. The cassock is typically made of black or dark-colored fabric, and is designed to be worn over a shirt and trousers.
In the Catholic Church and other high church traditions, the cassock is often worn by priests, deacons, and other members of the clergy as a symbol of their religious office. The cassock may be worn on its own, or it may be worn with additional vestments such as a surplice or a stole.
In some Protestant denominations, the cassock is less commonly worn, but may still be used as a liturgical vestment for certain occasions. It may also be worn by choirs or other groups that perform a liturgical function within the church.
The design of the cassock can vary somewhat depending on the particular tradition or context in which it is worn. In some cases, the cassock may be buttoned all the way up to the neck, while in other cases it may be open at the collar. The sleeves of the cassock may be wide and flowing, or they may be more closely fitted to the arms.
Overall, the cassock is an important symbol of the Christian clergy, and is considered to be a mark of respect and honor for those who wear it.