What's the main difference between a "ceremony" and a "ritual?"

Native speaker’s answer
Rebecca
The difference is that a "ceremony" is for a special occasion, a kind of event or celebration, and is usually performed once, whereas a "ritual" is done for its symbolic value of actions and implies repetition. Although, many ceremonies are considered rituals. Ex: At the wedding ceremony, we'll perform the ritual of lighting a unity candle. => at the event, they'll perform a ritual Ex: We did the ritual of throwing our graduation caps into the air at our graduation ceremony.