Yom Kippur is an important Jewish holiday that is observed by Jews and Atoners. It is a day of fasting, prayer, and repentance for the sins of the past year. Jews observe Yom Kippur by abstaining from food and drink, refraining from work, and attending synagogue services. Atoners also observe Yom Kippur by fasting, praying, and repenting for their sins. Both Jews and Atoners are expected to seek forgiveness from those they have wronged and to forgive those who have wronged them.