Which Jewish prayer book contains the Yom Kippur services?

The Jewish prayer book containing the Yom Kippur services is called a machzor.

A machzor is a specialized form of the siddur, the prayer book used for regular weekday and Sabbath worship. It contains the distinctive prayers, biblical readings, responsive passages, and liturgical poems required for major festivals. High Holy Day machzorim generally cover Rosh Hashanah and Yom Kippur, often in one volume or as companion volumes.

The Hebrew word machzor means “cycle” or “ 돌아오는 cycle,” reflecting the recurring annual calendar. Earlier Jewish prayer books sometimes used the term for a complete yearly collection of prayers; over time, the word came to refer more specifically to festival prayer books. The spelling may appear as machzor, mahzor, or maḥzor.

A machzor is not the same as a Haggadah, which guides the Passover seder, or a Chumash, which contains the Torah text divided for public reading. Mishnah is a body of rabbinic legal teachings, not a prayer book. Editions differ by Jewish rite and movement, so wording, melodies, and added poems can vary considerably.