The term "High Priest" in the Bible refers to the highest-ranking priest in ancient Israel, responsible for overseeing the religious functions and rituals of the Levitical priesthood. The role of the High Priest is particularly significant in the context of the Day of Atonement (Yom Kippur), when the High Priest would enter the Holy of Holies in the Tabernacle (and later the Temple) to make atonement for the sins of the people (Leviticus 16:29-34). The High Priest wore distinctive garments, including the ephod and the breastplate, which held the Urim and Thummim used for divination (Exodus 28:30).In the New Testament, the concept of the High Priest is fulfilled in Jesus Christ, who is described as the ultimate High Priest in the order of Melchizedek (Hebrews 4:14-16; Hebrews 5:6). Unlike the earthly High Priests, who had to offer sacrifices for their own sins as well as the sins of the people, Jesus offered Himself as a perfect sacrifice once and for all, establishing a new covenant between God and humanity (Hebrews 10:11-14). Thus, the High Priest serves as a crucial figure in understanding both the sacrificial system of the Old Testament and the redemptive work of Christ in the New Testament.