A Sunday school is an educational institution, usually (but not always) Christian in character. Sunday school classes usually precede a Sunday church service and are used to provide catechesis to Christians, especially children and teenagers, and oftentimes adults as well. Churches of many Christian denominations have classrooms attached to the church used for this purpose. Many Sunday school classes operate on a set curriculum, with some teaching attendees a catechism. Members often receive certificates and awards for participation, as well as attendance. Due to the fact that Sunday school classes precede morning worship on the Lord’s Day, many provide a light breakfast, such doughnuts and coffee, except on days in which Holy Communion is being celebrated due to the fact that many Christian denominations encourage fasting before receiving the Eucharistic elements.