Yom Kippur, or the Day of Atonement, is the holiest day on the Jewish calendar. Yom Kippur is one of the most widely observed of Jewish holidays, marked by a solemn, 25-hour fast and abstinence from wearing leather shoes, bathing, using perfumes or cosmetics and sexual relations. Yom Kippur concludes the Ten Days of Repentance, begun on Rosh Hashanah. As with all other major Jewish holidays, observant Jews also refrain from melachot, or creative labor, on Yom Kippur.

On Yom Kippur, we ask forgiveness and atone for the sins we have committed against G-d in the past year. Sins which we have committed against our fellow human beings may only be forgiven by directly asking the wronged party for forgiveness. Teshuvah plays a central role during the Ten Days of Repentance and especially on Yom Kippur. Teshuvah, perhaps best translated as repentance or return, is achieved when we come to sincerely regret what we have done wrong, have asked the one whom we’ve wronged for forgiveness and have made a sincere effort not to repeat the transgression in the future. In this way, teshuvah asks us to quite literally turn away from our past misdeeds and recommit ourselves to living up to being our best selves. If we have done the often taxing spiritual preparation, these days of deep introspection and reflection can allow us to begin with a clean slate.

The fast of Yom Kippur begins before sundown and lasts until nightfall of the following evening, when three stars are visible in the sky. There are five distinct prayer services on Yom Kippur, beginning with Kol Nidrei (All Vows) and Maariv or Arvit, the evening service, and continuing in the morning with Shacharit, the morning service, Musaf, the additional service, Minchah, the afternoon service and Ne’ilah, the closing service, begun right as the sun is about to set.

It is customary to wear white on Yom Kippur. Many people wear a kittle, a plain, white robe on Yom Kippur which is also traditionally worn on one’s wedding day and is also traditionally what a person is buried in. The tallit, or four-cornered prayer shawl that is traditionally worn only during Shacharit, the morning service is worn at all of the services on Yom Kippur, including Kol Nidrei, the only time that a tallit is worn in the evening.

Kol Nidrei is for many one of the most emotional and spiritual points in the Jewish liturgical year. Although it is a legal formula, the melody it is set to when chanted has moved people for centuries, conveying more emotion than the words alone.

After Kol Nidrei has been chanted thrice, we move into the evening service proper. During every service on Yom Kippur as part of the Amidah or standing prayer, we recite several confessions, the Ashamnu and the Al Chet. In total, we make ten confessions on Yom Kippur. There are many liturgical poems or piyyutim that are said on Yom Kippur.

The high point of both the Rosh Hashanah and Yom Kippur liturgy comes during the Musaf or additional service when we say the Unetaneh Tokef prayer which reminds us of the fragility of human life and existence as it asks the question, who shall live and who shall die. There has been an immense amount of commentary on this piyyut over the centuries.

Other important features of the Yom Kippur liturgy include the recitation of Yizkor or memorial service, as well as the Avodah, in which we reenact the rituals of the High Priest on Yom Kippur in the Temple. Yom Kippur was the only day on which the High Priest or Kohen Gadol was permitted to enter the Holy of Holies, Kodesh Kodeshim. At each point when the Kohen Gadol would recite the ineffable name of G-d, we fully prostrate, the only time when full prostration is done in Jewish worship aside from the Great Aleinu, also done on Yom Kippur and on Rosh Hashanah as well.

Yom Kippur also includes the martyrology service, in which is recounted the deaths of ten great rabbis and sages, all killed for their Jewishness by the Roman Empire. Some will also take this as an appropriate time to remember others who lost their lives on account of their Judaism, including those who died during the crusades, pogroms and Holocaust.

There are special Torah readings for Yom Kippur. The Torah is read both in the morning and afternoon. In the morning, Leviticus, chapter 16 is read and in the afternoon, Leviticus 18 is read. The haftarah or portion from the prophets for Yom Kippur morning is an incredibly powerful passage from Isaiah, asking us to take a hard look at ourselves, our fast and our society. I find it to be one of, if not the most powerful haftarot of the year. In the afternoon, the Book of Jonah is read in its entirety.

At the end of Ne’ilah or the closing service, the shofar is blown, a single tikeiyah gadolah, signaling the end of Yom Kippur. At this point, many congregations quickly pray the weekday evening service before people go off to enjoy a break fast with family and friends.

This article first appeared on BellaOnline.com.