RG Specs

Until recently, it was difficult to decide which side of the Format Wars to favor. Both HD-DVD and Blu-ray had their advantages and disadvantages. Now, with Blu-ray having won, the question probably seems less important. However, it’s still important to know these things: like the Beta vs. VHS debacle, this sort of thing will likely come to your attention again.

High-Definition

High-definition video (HD) offers a much better picture than standard-definition video (SD). In order to effectively use Blu-ray players (or even the now-defunct HD-DVD players), a high-definition television will be necessary, as Blu-ray and HD-DVD offer little advantage besides higher definition. High-definition, in simple terms, means higher image resolution. Image resolution describes how much detail is available on screen. Higher-definition televisions will show more detail.

via Blue Ray DVD Players Vs HD DVD Players | eHow.com.