Media corporations have always used the term copy protection, but critics like Richard Stallman argue that the term tends to sway the public into identifying with the publishers, who favor restriction technologies, rather than with the users.Copy prevention and copy control may be more neutral terms. "Copy protection" is a misnomer for some systems, because any number of copies can be made from an original and all of these copies will work, but only in one computer, or only with one dongle, or only with another device that cannot be easily copied.
More recently, publishers of music and movies in digital form have turned to encryption to make copying more difficult. CSS, which is used on DVDs, is a famous example of this. It is a form of copy protection that uses 40-bit encryption. Copies will not be playable since they will be missing the key, which is not writable on DVD-R or DVD-RW discs.
The fact is there are no new "copy protections"? To create a new copy protection, you would also have to change the way a DVD player works. DVD players must all conform to rigid specifications to ensure proper playback. A new copy protection cannot be introduced unless the DVD player specification changes.
You can however author a DVD (the process of writing the original DVD) in such a way as to make it difficult to copy if you exploit weaknesses in the design of DVD copy software. A great deal of effort has been spent on trying to make new DVD movies difficult to copy, but still playable on a DVD player. Some simple examples are the inclusion of bad sectors (defects analogous to scratches) or bad DVD structure (adding bogus content to a DVD) which are blatant attempts to inhibit archival programs from making backup copies of the DVD.