A catechism has been defined as "a summary of principles, often in question-and-answer format". Documents of religious instruction have been written since the beginning of Christianity and the catechism is typically an assemblage of these smaller documents into one large compilation of Church doctrine and teachings. The Catechism of the Catholic Church, for which the usual English-language abbreviation is CCC, is instead a source on which to base such catechisms and other expositions of Catholic doctrine, called a "major catechism." It was given, as stated in the Apostolic Constitution Fidei depositum, "that it may be a sure and authentic reference text for teaching catholic doctrine and particularly for preparing local catechisms." The CCC is in fact not in question and answer format. - from Amzon