Leviticus is the third book of the Hebrew Bible and the Christian Old Testament. It is named after the priest Levi, who is considered the central figure in the book due to his ancestry and the focus on priestly laws and rituals. Leviticus covers a wide range of religious, moral, and ceremonial laws, including offerings, sacrifices, purity, and holiness. It is often studied by those interested in Jewish and Christian theology and religious practices.