See "Footprint". If there is a difference between a footprint and a module, I have yet to discover it!
Most of what I have to say about modules/ footprints is over at the "footprints" page. However, do note the following…
One little "gotcha": The wiki you are reading was created with the excellent, free, service from http://Wikidot.com. They also use the term "module". I have tried to bury WikiDot's use of the term "module". (If it still appears on the site you are reading in a place that might confuse a beginner, please write, tell me where?)
(This entry may need editing. If you particularly want THIS edited, write and cite "Page co1modu")