A biretta is a square-shaped hat traditionally worn by clergy in the Roman Catholic Church and some other Christian denominations. It is typically made of black or colored fabric and features three or four peaks, with a pom-pom or tassel on top. The biretta is often worn during liturgical ceremonies and signifies the wearer's rank within the church. The biretta has its origins in the medieval period and has evolved over time. It is commonly associated with cardinals, bishops, and priests, and is sometimes used in academic settings by those holding advanced degrees in theology.