Modular Engine

For years I have heard the term "Modular Engine". I was always embarresed to ask what that meant until recently when I discovered that no one really knows.
So I have come to the experts. Help a dummy (or a bunch of dummies). What is a modular engine?

Here is a site that has a blurb about the Modular Ford motor:

http://www.answers.com/topic/ford-modular-engine

The term "modular" means that the design can be expanded from a six to an eight to a ten cylinder engine.....and all the variations of cam locations, etc. But really, it is a name for a family of engines like was Windsor, Cleveland, etc. Some guy gave a presentation about the new engine design that was "modular" and touted that the engineering cost would be lower.....and the managers bit on it.....each engine size is a system that is designed for a certain task......and you cant take a modular six cylinder head and bolt it to a V8! There can be parts interchange, etc. that lowers design/production costs.

Thank you very much ! ! I had an idea it was something like that. You guys are great ! !