Yom Kippur, also known as the Day of Atonement, is the holiest day of the Jewish year. It marks the culmination of the 10 Days of Awe, a period of introspection and repentance that follows Rosh Hashanah, and is typically observed with a 25-hour fast followed by a special religious service that evening. It is a holiday where Jewish people ask for forgiveness from others they might have wronged.