Are all widescreen TVs High Definition?
Not really. You’ll find a lot of widescreen LCD TVs in the market, but unless they support 720p, they’re not high definition. Most of these TVs support a native resolution of 848x576 (PAL), and fewer of them support progressive scan (576p).
They are good for general purpose TV viewing or watching a movie on DVD, but they still can’t really match up to the kind of quality you’ll get from true HD.
Are DVDs High Definition?
DVDs have a native resolution of 720x540 (NTSC), which is not exactly ‘true HD’. But most home DVD players these days support a technique known as ‘up-scaling‘, which basically stretches the DVD’s output resolution to high definition size.
As bad as that may sound the results are usually quite good in the up-scaled images and usually surpass the quality you get to see in the native resolution. Of course it all depends on the quality of the DVD player and the cables you’re using.
How will normal TV appear on an HDTV?
Unless you have subscribed to a dish service (like DishTV, Tata Sky, etc.), the image quality would be pretty bad. The reason for this is that cable TV in India comes from an RF (Radio Frequency) cable, which gives the lowest signal bandwidth possible. Dish services require you t use a digital decoder that gives you output via composite (Audio/Video) cables that give you a much higher quality in comparison.
Still, we don’t have any high definition broadcasting station in India yet, so it would be unfair expecting DVD quality imagery from any form of cable signal.
does it matter if you sit 10 feet away can you make out difference between them at this distance 
