This great FAQ should be helpful for all the newbies who are wondering what telesync, CAM, screeners etc are.

720p/1080p
A copy of the final released Bluray. This is the highest quality available for download. Usually 4.7GB or more. These rips are released in MKV containers. To play these video files your PC/Mac must be able to play at least 720p HD content.

DVDRip
A copy of the final released DVD. If possible this is released PRE retail (for example, Star Wars episode 2) again, should be excellent quality. DVDrips are released in SVCD and DivX/XviD.

R5 (DVD Region 5)
Made with a telecine machine from an analog source. Unlike a TC the digitization is performed by the studio itself with very professional (and expensive) equipment and usually from the original source. The purpose of it is to create a high quality digital copy (usually for a later DVD release). But unlike a DVD, an R5 is released before the digital post-processing is finished. The quality of the rips can differ, but an R5 can be almost indistinguishable from a DVDRip since many movies are published on DVD with minimal editing.

DVD-SCREENER (DVDscr)
Same premise as a screener, but transferred off a DVD. Usually letterbox , but without the extras that a DVD retail would contain. The ticker is not usually in the black bars, and will disrupt the viewing. If the ripper has any skill, a DVDscr should be very good. Usually transferred to SVCD or DivX/XviD.

SCREENER (SCR)
A pre VHS tape, sent to rental stores, and various other places for promotional use. A screener is supplied on a VHS tape, and is usually in a 4:3 (full screen) a/r, although letterboxed screeners are sometimes found. The main draw back is a “ticker” (a message that scrolls past at the bottom of the screen, with the copyright and anti-copy telephone number). Also, if the tape contains any serial numbers, or any other markings that could lead to the source of the tape, these will have to be blocked, usually with a black mark over the section. This is sometimes only for a few seconds, but unfortunately on some copies this will last for the entire film, and some can be quite big. Depending on the equipment used, screener quality can range from excellent if done from a MASTER copy, to very poor if done on an old VHS recorder thru poor capture equipment on a copied tape. Most screeners are transferred to VCD, but a few attempts at SVCD have occurred, some looking better than others.

DDC
DDC stands for Digital Distribution Copy. It seems it may be a copy released to places like NetFlix (a service available in America) and has been leaked from there. Quality is almost DVD like even though the encode is not the best.

WORKPRINT
A workprint is a rough version of a motion picture, used by the film editor(s) during the editing process. Such copies generally contain original recorded sound that will later be re-dubbed, stock footage as placeholders for missing shots or special effects, and animation tests for in-production animated shots or sequences. Workprint usually comes with a timecode. These copies has often missing scenes

TELECINE (TC)
A telecine machine copies the film digitally from the reels. Sound and picture should be very good, but due to the equipment involved and cost telecines are fairly uncommon. Generally the film will be in correct aspect ratio, although 4:3 telecines have existed. A great example is the JURASSIC PARK 3 TC done last year. TC should not be confused with TimeCode , which is a visible counter on screen throughout the film.

TELESYNC (TS)
A telesync is the same spec as a CAM except it uses an external audio source (most likely an audio jack in the chair for hard of hearing people). A direct audio source does not ensure a good quality audio source, as a lot of background noise can interfere. A lot of the times a telesync is filmed in an empty cinema or from the projection booth with a professional camera, giving a better picture quality. Quality ranges drastically, check the sample before downloading the full release. A high percentage of Telesyncs are CAMs that have been mislabeled.

CAM
A cam is a theater rip usually done with a digital video camera. A mini tripod is sometimes used, but a lot of the time this wont be possible, so the camera make shake. Also seating placement isn’t always idle, and it might be filmed from an angle. If cropped properly, this is hard to tell unless there’s text on the screen, but a lot of times these are left with triangular borders on the top and bottom of the screen. Sound is taken from the onboard microphone of the camera, and especially in comedies, laughter can often be heard during the film. Due to these factors picture and sound quality are usually quite poor, but sometimes we’re lucky, and the theater will be fairly empty and a fairly clear signal will be heard.