Component Cables vs. HDMI Cables

Is there a huge difference between hd component cables (the cables with 3 video and 2 audio ports, NOT the packaged cables) and HDMI cables.

I figure there's probably a difference or HDMI cables would be pointless but is the difference major?

Component cables have a resolution limit, HDMI cables do not. The highest resolutions you can get with component (if your TV or home theater receiver can also support them over component) are:

Video games: 1080p

Blu-ray movies: 1080i

DVDs: 480p (upconversion not allowed over component)

HDMI cables also allow uncompressed PCM surround audio, and HD Bitstream audio (Dolby TrueHD, DTS-MA), all master quality audio formats in 5.1 and 7.1. You could use an optical cable for audio with component video, but would be limited to the old Bitstream formats (Dolby Digital, DTS), which are good but still less than master quality. The red and white audio cables that some component connectors have are limited to 2.0 stereo, so not even 5.1 surround is allowed.