This guide will hopefully help you
1) figure out what the different types of connections are,
2) decide which connection to use,
or 3) buy a tv with the inputs that you need now, and might need in the future.
Analog Video: RF/CoaxialCoaxial_male.jpg
Coaxial cable is the cable that you likely have in your home connecting from the cable company, a satellite dish, or an antenna.
There are 2 popular types of wire used, RG6 and RG59. RG6 is the better of the two and should always be used whenever possible.
RG59 is slightly thinner, therefore easier to bend. It should be fine for short runs (example from wall socket into television/vcr/digital (STB) box/DVD Recorder).
RF Cable is good for sending multiple signals through one cable (for example your hundreds of analog and digital tv channels, phone service, and internet). It is not however the most efficient as it can easily accept interference between devices cause the final picture to be inferior to other types of connections (below). Try to avoid using coaxial to connect components to each other.
Analog Video: Compositecomposite_female.jpgComposite_male.jpg
Composite cable was once the standard for connecting components to each other. Examples that commonly use composite are game systems, dvd players, VCRs, etc. The luminance and chrominance signals travel together and this is therefore typically inferior to the next types of connections that you will read about.
Analog Video: S-VideoSVideo_female.gifSVideo_male.jpg
S-Video is the next step up from Composite because it seperates the luminance and chrominance signals.
The S-Video connection can sometimes be inferior to a Composite connection (for analogue TV stations), if the "source component" has sent the signal through a comb filter, because the comb filter in your TV may be better at doing this than the source component.
Try both and see which is better.
Analog Video: Component videoComponent_female.jpgComponent_male.jpg
Component video is the best analog video connection type. It takes S-Video one step further by separating the signal into 3 separate signals rather than 2.
Component video is capable of carrying signals such as 480i, 480p, 576i, 576p, 720p, 1080i and 1080p, although some TVs do not support 1080p through component video.
This is the only analog connection type that will carry High Definition.
Usually component is inferior for carrying Standard Definition signals.
Digital Video: DVIdvi_female.jpgDVI_male.jpg
DVI can be called the digital equivalent of Component video. It is designed for carrying uncompressed digital video data to a display.
DVI is currently the standard in computer monitor hookup to your computer.
DVI is also compatible with HDMI (below), by use of HDMI-to-DVI cables, without requiring any extra hardware to convert signals in between.
Digital Video: HDMIHDMI_female.jpgHDMI_male.jpg
HDMI is basically DVI plus digital audio.
DVI is compatible with HDMI by the use of HDMI-to-DVI cables. However, no audio signal is sent in this way.
When planning to hook up a computer (DVI Output) to a television (HDMI) a seperate wire carrying audio from computer to television will be needed.
When buying a new tv and planning to do what I mentioned above, make sure that at least one of the HDMI inputs of the new TV has a seperate input for audio.
Some computer video cards are beginning to include HDMI output, some with of which will also send audio through that HDMI connection.
Up until recently all audio connections were made using this type of connection. Each cable carries one channel (or one speaker). To get mono sound either the white (left) or red (right) wire can be used.
To receive 5.1 or 6 channel audio some receivers have 6 seperate RCA connectors (3 red, 3 white) for each input, which can be used if your output device (Digital Box, DVD Player, etc.) has that many rca outputs.
This can get very messy.
Toslink is a standardized optical fiber connection system. Its most common use is in consumer audio equipment (via a "digital optical" socket), where it carries a digital audio stream between components
There is a modulator at each end that translates the signals from electrical to light and back.
Toslink cables must be limited to below 10 meters or, in many cases, under 5 for reliable transmission unless using a signal booster.
Audio: Digital Coaxial CableSPDIF_male.jpg
SPDIF stands for Sony Phillips Digital Interface.
Toslink (described above) is also an SPDIF specification connection, but when someone mentions SPDIF it usually refers to Digital Coaxial.
Sony/Phillips developed this coaxial connection as a method of getting digital audio signals from one component to another. People may argue whether Coaxial or Toslink is better, but let’s just say they are both excellent and better than analogue audio. For coaxial, you should get an "RCA-type" connection with an impedence of 75 ohms instead of the regular 50 ohm audio cable.