The most common type of video cable is called composite video. A composite video cable consists of one yellow RCA connector that's usually bundled with red and white RCA analog audio cables. It's called composite video because all of the video information -- color, brightness and sync -- is composited, or squeezed, onto one cable [source: Miller]. Composite video cables were designed for older TVs and have a maximum resolution of 330 lines. They're fine for watching VHS tapes on the old TV in the basement, but if you have a newer television, or an HDTV, composite video cables simply won't cut it.
S-video cables are a step up from composite video with a maximum resolution of 400 lines. You will recognize an S-video cable by its circular, nine-pin connector. S-video separates color information from picture information, resulting in a crisper image. Although S-video jacks are found on a lot of TVs, DVD players and home theater receivers, the cable's initial popularity was quickly eclipsed by component video.
Component video cables consist of three RCA connectors colored red, green and blue. With component video, not only is color separated from picture, but the color portion is split into two separate signals [source: Miller]. The result is a super-sharp image with deep color saturation. Component video cables are ideal for connecting high-definition video components like Blu-ray players and HDTVs. Most home theater receivers come with several sets of component video jacks.
DVI (digital video interface) cables were designed specifically for use with HDTVs and other high-definition video components. They have large, 18-pin connectors that look like computer cables. DVI cables offer the exact same image quality as component video cables, except that DVI comes with a built-in copy protection protocol called HDCP (High-bandwidth Digital Content Protection). Critics of DVI claim the built-in copy protection mechanism causes compatibility problems with certain devices.
Lastly, we'll look at three kinds of cable that carry both audio and video signals.