The 17-book Macropædia is the third part of the "Encyclopædia Britannica", and the other two parts are the 12-book "Micropædia" and the 1-book "Propædia". The name comes from the word "macro" and "encyclopaedia". Macro means big, and so, the Macropædia is a big encyclopaedia. The Macropaedia has articles that are very detailed, but one article is usually about a very large topic. It is the opposite of the Micropædia, which has articles that are short. 