Composite video (also called FBAS) is the standard that connects almost all consumer video equipment - television sets, laser disc players, VCRs and camcorders.
Composite video combines the three basic elements of a video picture (color, brightness, and synchronization data) into a single combined composite signal.

Usually composite video is transmitted over 75 ohm cables with BNC connectors. Long video cables are prone to signal loss and RF interference. The 75 ohm cable chain must be terminated at both ends.

S-Video (also called Y/C or component video) is carried on cables that end in 4-pin Mini-DIN connectors.
The S-Video (also called Y/C or component video) signal separates color and brightness into two separate channels on two separate cables. This makes for a sharper picture image, with less granularity, on the receiving device.

S-Video for consumer devices is carried on cables that end in 4-pin Mini-DIN connectors. These cables are made up of two separate small cables in one jacket. In professional installations S-Video is mostly carried on two separate cables with BNC connectors.

The luminance (Y) is the black & white portion, providing brightness information. The chrominance, or chroma (C) is the color portion, providing hue and saturation information.

(Three-wire component video signal is split into three parts; black and white information (Y), and two colour difference signals (Pb and Pr).)

SVHS is not a video transmission signal, rather it is a tape format which is almost always used in decks that support the S-Video signal standard. These two terms, S-VHS and S-Video, are often used interchangably to refer to S-Video.

RGB requires three, four or five (depending on the sync characteristics) cables. Generally, it is similar to S-Video. Three of the conductors carry color information for the red, green and blue components: R,G,B. The conductors H and V are used for synchronization (horizontally and vertically). If less than five conductors are used, there are different versions to integrate the sync information into the signal.

NTSC stands for National Television Standards Committee. It is the video transmission standard for North and Central America, including Mexico and Canada, and Japan. Its technical format is 525 lines per frame with roughly 30 fps (frames per second) refresh rate. It is pretty much synonymous with composite video when talking about a video signal, but is not necessarily equivalent to the output from a video capture card that may claim to be NTSC-legal.

PAL (Phase Alteration Line) is the European counterpart to the NTSC standard. It has a higher vertical resolution (625 lines per frame) but a lower refresh rate (25 frames per second) that can cause flickering. It is the standard for the UK, Western Europe, the Middle East, and parts of Africa and South America.

SECAM (Systeme Electronic Pour Couleur Avec Memoire) is very similar to PAL. It specifies the same number of scan lines and frames per second, but differs in that chrominance (color) is FM modulated. It is the broadcast standard for France, Russia, and parts of Africa and Eastern Europe.