copy or not copy?

First of all, DRM is for Digital Rights Management. It's a group of different protection systems which protect digital files from copy. This solution allows the protection of the files so that they can only be plugged into the right player, and keeps away the unprotected transfer of these files.
That's the reason why the DRM offers a narrower broadcasting of the files' content and defines more precisely the parameters of the digital files. From that, it becomes possible to control how many times the file can be downloaded or read, or how long it's gonna be available for example.
The main problem with the digital technology, and especially with the rights' protection, is still the hacker's presence on the commercial field. It seems almost impossible to reduce this threat to zero, yet, the goal reached by the editors is more to keep the hackers back as much as possible more than trying to stop them. Indeed, edition and hacking problem were born at the same time. Digital technologies have grown a phenomenon which was already existing.

http://www.drmwatch.com/