DVDrip and DVDscr are both terms used to describe digital video files, usually associated with movies. The terms themselves merely describe the way the video file was produced. However, in most contexts, distributing the video files described in this way will breach civil or criminal law.
DVDrip refers to a digital video file that is made by directly copying the video files from a DVD rather than re-encoding the video or converting it to a different format. DVDscr (DVD screener) refers to a video file that is either on or taken from a disc provided before the movie is released for sale to the general public. Often the disc is issued while the movie is in cinematic release or even before this release, for example to a reviewer or awards judge. In both cases, the term indicates the video file should be of the same quality as the original DVD.
The terms DVDrip and DVDscr are most commonly associated with file descriptions used in listings for online movie-file sharing services, often involving illegal reproduction. Possessing a DVDscr disc is usually legal only if you are the authorized recipient: Copying the content or even passing on the original disc to somebody else may be illegal. Distributing a copy of a DVD without authorization is a criminal and civil offense in many jurisdictions. In the United States, merely making a DVDrip file may be a crime, even if you don't distribute it. The Digital Millennium Copyright Act outlaws most software that can be used to circumvent copy protection tools, such as those used on many commercial DVDs.