Well, you can. You can also convert it in the opposite direction. The tool for doing this is known as 'alien' and this is an overview:
Feedback is pretty awesome.
Use an RPM on a DEB-based System • Linux Tips
Once in a while, you'll come across software that's only in RPM format. It's possible to convert RPM to DEB and you may be able to install that software on your DEB-based system.
linux-tips.us
Feedback is pretty awesome.