How To Choose Cable Connections
Composite cables, aka RCA cables are the standard "free-in-the-box" cables we are all familiar with. When no other connection is available, then RCA cables are fine. Although, we recommend that you choose good quality cables.
Digital Audio Coaxial uses coaxial cable that is essentially the same as the video coaxial (RF) cable mentioned below. However, when used for audio, RCA connectors are used. This cable is capable of carrying a high quality digital audio signal.
Optical cable uses Toslink connectors and so the cable is often referred to as Toslink cable. Because it carries a signal of light impulses, it is nearly impervious to interference and cable length is not an issue. As to sound quality, there is no evidence that it is superior to digital coaxial, nor is there a consensus amongst listeners.
RF (aka Coax, Coaxial) cable is a round shielded wire that is most often used to bring a cable or antenna signal into your home. This 75ohm cable uses an "F" type screw-on connector. For video signals, its use should be limited to bringing the signal indoors. Other cables provide better signal carrying capabilities between components. For long runs of cable or for DSS, invest in RG6 (rather than RG59) because of its lower signal loss.
Composite cable, aka RCA cable, combines signals and carries them in one wire. It is used for both video and audio. A common configuration is three wires fastened together; one wire (yellow) for video, one wire for the right audio channel (red) and one wire for the left audio channel (white). This cable uses the standard RCA slip-on connectors. It gets the job done, but it will not carry HD or progressive scan signals. It is the minimum grade of cable to be used in a home theater set up. If your equipment will support a higher quality connection, use it.