questions about HD tvs (setup and others..) as well as wide/full screen?

Question

hello everyone. we just purchased a Sony 46" LCD TV and its great and blahblah (if not a bit big.. hehe). well now my dad tells us we must buy HD tv services instead of regular cable or something. (or something like "digital cable with HD.")

anyways, what are the steps? i know that news channels such as "eyewitness news 7" are in high definition, but what does that mean? does that mean that for the viewers with regular TVs, the "HD" doesnt make a difference? and for viewers with PLasmas and LCDs and all that good stuff, it does make a difference? thats a wild guess im taking but basically,
im asking HOW DO PARTICULAR CHANNELS/NEW STATIONS BEING IN "HIGH DEF." AFFECT THEIR AUDIENCES? is the difference in the TV itself or the type of cable service we have??

CONTINUED BELOW AS I HAVE RUN OUT OF SPACE--

also, whats the difference between widescreen and fullscreen dvds? this is my take:
widescreen dvds are for widescreen TVs. they are "wide" and stretch to fit widescreens.
full screen dvds will work on widescreen TVs but not as "fitting" (wide) as widescreen DVDs. okay i suppose this part i understand.

but what i really need clarification on is this: the DVDs that are sold nowadays are all the same, yes? the only options they come with is wide or full screen, yes? (like no "HD dvd" and "non HD DVD".) so otherwise, each dvd's quality should all be the same on a LCD, Plasma, old tube tv correct? so if i buy a Devil Wears Prada DVD in full screen, it wont look WORSE than one thats in widescreen, correct? (in terms of picture quality and width.)

what im asking is

Answer 1

check this out

http://www.cnet.com/4520-7874_1-5137915-1.html

the definition is in the pixels

Full HD (1080p) is only available from a HD or Blue Ray DVD player.

HD broadcasts are 1080i.

right now u are looking at a blown up picture of standard def (480i) which is up converted by the set. It looks good to u only because it is big.

when u get an HD broadcast on there u won't believe what u missed.

Answer 2

Ratio