From Wikipedia: A catechism ( /?kæt?k?z?m/; Ancient Greek: ?????????? from kata = "down" + echein = "to sound", literally "to sound down" (into the ears), i.e. to indoctrinate) is a summary or exposition of doctrine, traditionally used in Christian religious teaching from New Testament times to the present. Catechisms are doctrinal manuals often in the form of questions followed by answers to be memorized, a format that has been used in non-religious or secular contexts as well. ~~~ Development and usage of systematic catechisms is unique to Western Christianity. Besides some exception, training catechumens in Eastern Christianity is carried out in case by case. As defined in the Catechism of the Catholic Church, paragraph 5 (quoting John Paul II, Apostolic Exhortation Catechesi tradendae 18): Catechesis [/?kæt??ki?s?s/ -WP] is an education in the faith of children, young people and adults which includes especially the teaching of Christian doctrine imparted, generally speaking, in an organic and systematic way, with a view to initiating the hearers into the fullness of Christian life. ~~~ A catechist is one who engages in such religious instruction. Typically, it is a lay minister trained in the art of catechesis. It might also be a pastor or priest, religious teacher, or other individuals in church roles (including a deacon, religious brother or sister, or nun). The primary catechists for children are their parents or communities. A catechumen is one who receives catechetical instruction. ~~~ The Catechism of the Catholic Church (see below) is the catechism that is in most widespread use among Catholics today. It is the official Catechism of the Church. ~~~ For Catholics, all the canonical books of the Bible (including the Deuterocanonical books), the Tradition of the Church and the interpretation of these by the Magisterium (which may be outlined in a catechism, a compendium or a declaration) constitute the complete and best...