On Yom Kippur, adults fast. After a special meal before sundown, adult Jews do not eat or drink again until after sunset the next day. Jewish adults fast on Yom Kippur for many different reasons, but the main idea is that by removing all distractions (such as eating) we are better able to focus on prayer. The long day is typically spent in synagogue praying and asking God for forgiveness for the mistakes of the past year.
As Yom Kippur approaches, people may greet each other by saying Tzom Kal, which means “Have an easy fast.”
Typically, children younger than bar/bat mitzvah age do not fast. But they can begin to recognize that Yom Kippur is a time to take care of others’ feelings and to improve their own actions toward others. You can talk with your child about reasons that adults fast, and perhaps your child may choose to forgo a snack, or give up a favorite food for the day.