What is CPRM

HI

I recently bought a JVC combi DVD/HDD/VCR and bought some blank discs to record to. I notice that on the packaging it says that it is “with CPRM”
I understand that it is some kind of copyright protection. What I would like to know is, what difference is there between a disc that has it, and one that doesn’t have it. I have looked up CPRM on these sites but can’t find the info I want, Any help would be appreciated.

Cypriana

i typed “What is CPRM” into google, and the first two sites returned were very helpful

definition: http://www.google.com/search?hl=en&hs=9eC&lr=&safe=off&client=firefox-a&rls=org.mozilla:en-US:official&oi=defmore&defl=en&q=define:CPRM

explanation: http://www.theregister.co.uk/2001/01/10/everything_you_ever_wanted/