Because HDMI is a digital interface, it provides the best quality video since there are no lossy analog to digital conversions that are required for analogue connections (such as component or S-video). The difference is especially noticeable at higher resolutions such as 1080p. Digital video will be sharper than component, and eliminates the softness and ghosting found with composite. Small, high contrast details such as text bring this difference out the most.
High Speed Cable
Supports screen resolutions of 480p, 720p 1080i, 1080p at 60 frames per second, and 1080p at 120 frames per second it also supports "Deep Color" or a frequency response up to 340 MHz.
Gold Plated Connectors
The difference is that gold will not corrode. If you live in a coastal or high humidity location the connection points between your cables, displays and sources will corrode over time if you use anything but gold. The corrosion that builds up is not as conductive as the base metal and will result in a degradation of the signal. This is particularly so if you have a lot of connections or are running cables longer than 15 feet.