Coaxial wiring is commonly used in home cable systems. It carries sound and video over a single wire. For interconnecting audio and video components, and for connecting game consoles, this has become mostly obsolete.
Composite Video (RCA)
Composite video uses a single wire, usually colored yellow on the ends, to carry a video signal. This is the lowest quality method of connecting a video source to a monitor. These types of connectors are rapidly becoming obsolete as they are replaced by S-video, Component video, and DVI.
For people in Europe, many televisions have a SCART connector. If your TV does not have a composite video connection but does have SCART, a simple conversion plug is available to convert a RCA connection to a SCART connection.
S-Video works by separating the chrominance (color) and luminance (brightness) into two seperate pairs of wires. This leads to a higher quality picture than composite. While it is more advanced than its earlier cousin, s-video is also on its way out, in favor of DVI and Component connections
As with composite connections, in Europe a SCART convertor is widely available to connect a S-Video connector in a SCART socket.
Component Video (YUV)
Component video consists of three seperate wires, each transmitting information (colour, luminance, chrominance) used in televisions and monitors. Because this information is not combined into one wire, the signal strength and picture quality is much higher. This is currently the dominant standard in the United States.
The SCART connector is a standard connector used in Europe. SCART can accept true RGB signals as well as composite and S-Video signals. If your videocard can output SCART RGB signal, this is the best quality available through a SCART connector.