There are two main types of video signals: analog and digital. Analog has been the standard for decades, but today's advancements in technology have produced supirior digital image and sound that has changed the face of home theater quality.
Here are the options for
video cables, in order of quality:
F-Type (RF) Coaxial Cables – These
cables are the most common and the least desirable for AV connections. With the audio and video signal 'modulated' onto one
cable, it is impossible to transmit as high a quality of signal as what can be carried by a component,
S Video, or even a composite
video cable. F-Pin connections supply only mono audio, not stereo.
Composite (RCA) Video Cables – Composite
video cables represent a step up from standard
coaxial cables. They feature what is called a RCA connector (RCA connections are now considered the standard on most TVs, DVDs, and VCRs); but, as with F-type
cables, all video signals are carried on a single conductor, which is not an ideal form of transmission.
BNC Video Cables - Used primarily in the professional broadcast domain, BNC (short for Bayonet Neill Concelman, after the two engineers responsible for its invention)
cables are actually the same as
composite video except for the shape of the connector, which screws into place and is more secure than an RCA connector.
S-Video Cables – These
cables are a significant step up from
composite video. By breaking the video signal into two component parts,
S-video cables greatly improve picture quality over composite
video cables.
S-video inputs are found on most high-end TVs and AV components.
Component Video Cables – These are the best non-digital
cables for high definition video. They break down the video signal into three
cables, so image clarity and sharpness is maximized.
Component cables look just like
composite cables (both use RCA-type connectors), but since component
cables break down the video signal into three
cables rather than
composite cables' single
cable for video transmission, the signal quality is superior to the other types.
DVI Cables – Digital Video Interface is a relatively new type of connection that supplies unmatched video quality.
DVI maintains the pure video signal in its digital form from satellite and DVI-equipped DVD sources to the TV monitor or projector, thus providing the very best picture quality available.
HDMI Cables – High Definition Multimedia Interface is essentially a smaller version of DVI: it is backwards compatible with
DVI. However,
HDMI also carries 8 channel audio, which is not supported by
DVI ports, so this would be lost in the transition.
HDMI is a new technology that is available on high end DVD players, plasma and LCD screens, and HDTV.
VGA Cables – You may have seen
VGA (Video Graphics Assembly) cables before, especially if you've used a computer.
VGA is also referred to as 15-pin or HD15 because of the 15 pins on the male connector.