>I've been following this thread, and I really don't know a lot aout most of this stuff, so a simple question would be: What's the difference between middle teir front end ect.

You'll get a lot of responses to this question, many of which will be better than this one, but..

In a multi-tier environment the backend is where the database server (and ususally all the data) resides. The frontend is what the user sees and interacts with on his/her computer. The middle interfaces the frontend with the backend (and vice versa).

The ultimate goal isn't all that different from OOP in general. A multi-tier solution is flexible, extensible and (frequently) reusable/portable. The backend doesn't care what languange the middle tier is written in as long as it performs as expected. The middle tier doesn't care what language the frontend is written in as long as it performs as expected. Etc, etc.

HTH!