Keemo
Basically there are two main types of 3D modellers
"Block modellers"(as i know them), such as AutoCad, Autodesk Inventor etc. these are used for acurate models such as engines, heating systems and products.
There are also "vertex modellers"(as i know them), these are used for game developpment, animation etc. and it just a case of plotting vertex's and joining them together. although these are less acurate you can be more creative with them.
As for your second question
Quote: "is it compatible with DBP ?"
I'm sorry and don't have a clue, I will maybe try importing some of my Autocad models in to DBPro, not that they would be any use in a game.
Get back to you
ROCK