An HDMI cable transmits uncompressed digital audio and video feeds from an audio/video source to an audio/video monitor. The major benefit of an HDMI cable is that only one cable is needed for transmission, compared to the standard separate cables for audio and video. However, your television or computer monitor must have an HDMI port for it to work. These ports are generally on the back of the monitor, and are labeled "HDMI."
An HDMI cable is designed to give you a crisper, more focused digital picture when watching a television show or movie. The difference is most apparent when watching something in 1080p, or high-resolution programming. However, an HDMI cable alone is not the only factor to consider. While standard TVs can be converted to display digital programming using a digital converter box, TVs designed for digital TV -- such as HDTVs -- benefit more from HDMI cables. Simply put, an HDTV has been designed to display 720p and 1080p, while older analog TVs have not. The more advanced your TV or monitor, the crisper the picture will look.
HDMI cables are available in different versions; each version represents a new advancement in functionality. For example, HDMI 1.1 -- the first version to be released after version 1.0 -- added support for DVD audio. HDMI version 1.3 increased the single-link bandwidth speed. This increase in speed resulted in higher frame rates, higher resolution and deeper colors in HD displays. Three separate versions of HDMI 1.3 have been introduced: version 1.3, version 1.3a and version 1.3b. However, according to HDMI.org, the differences between the three are so minor that consumers aren't able to tell the difference.
A higher-priced HDMI cable does not mean a more dependable cable, according to CNet.com. The brand name attached to a cable -- such as Accell, Monster or Belkin -- also makes no difference in performance. Simply put, if you see a standard 6-foot HDMI cable selling for $50, it will do the exact same thing as a standard 6-foot HMDI cable being sold for $10.