Letís start at the beginningÖ Weíll talk lowest quality video signal transmission to highest quality. At the bottom of the video connection food chain is the lowly composite video connection. This implies that all the video information is lumped into one encoded signal by your source (say, a satellite receiver) and sent down the lone wire to your display monitor. Although the lowest in quality, it is also by far, the most common way to send video signals in todayís average consumer electronics. This connection requires the monitor on the other end to have an NTSC decoder built into it (NTSC is our current video standard here in the USA). Consequently, this connection can only be used for the NTSC standard ñ it simply doesnít have the necessary bandwidth to provide a higher quality signal transmission.

The next step up the chain is S-Video. This is a dual coax type system (even though thereís only one outer jacket in the typical S-Video cable) that allows the source to separate the luminance info (blacks and whites) from the chrominance (color info). By separating these two primary signal ingredients, the quality rises significantly, providing much improved color rendition and saturation, and better quality blacks and white with more accurate tracking in contrasted scenes. Despite these improvements, a two wire connection is still severely limited in bandwidth, so this connection is relegated to NTSC use as well.

The next one up the ladder is yet another NTSC standard but is now a 3 wire connection and also the ultimate for consumer equipment (RGBHV is available on broadcast equipment, but thatís a topic for another day). This is the Y, Cr, Cb connection. As you might imagine, it breaks the job up one more time, providing the luminance on the Y cable, the R-y for blue info, and the B-y for the red info. The green (notice that the signal is referenced to the three primary colors that make up all video colors) is sent along with luminance on the Y cable. This connection standard gives the best possible color accuracy and blacks to whites in todayís consumer electronics.

From here we move into the high resolution connections. At the bottom of this range is another 3 wire connection called Y, Pr, Pb. This is the standard for all DTV formats, set forth by the ATSC (read that, HDTV governing organization). It is quite similar to the Y, Cr, Cb format for NTSC video.

The next step is to move away from signals that need any kind of signal decoder and start delivering the actual raw red, green, blue, and sync (the signal that instructs the monitor on how to scan the image) info separately. The lowest quality way to do this is RGsB, wherein the red info is sent down one coaxial cable, the blue down another, and the green info, combined with the sync info is sent down the 3^rd wire.

To improve upon this we simply need to break out the sync information and send that down itís own wire. Hence, RGBS, with S meaning composite sync. Composite sync implies that both the horizontal line and the vertical refresh timing pulses are mixed together. Obviously, the RGsB mentioned earlier is a composite type sync configuration as well. 

Drum roll pleaseÖ.The ultimate connection possible for the highest resolution sources available isÖ.RGBHV. As you mightíve guessed, this is, again, red, green, blue, then the horizontal timing pulse (H sync) gets itís own wire, followed by the vertical refresh (V sync) riding down itís own wire as well. And there you have it ñ a connection that is exceedingly high in bandwidth capability that can pass anything you care to throw at it.