You have probably heard of HDTV but you may be confused by all of the new terminology.
The maximum resolution on a standard analog TV is 720 X 480 pixels, which is about 337,000 total pixels. HDTV is part of the Digital TV specifications which has many different video resolutions. The two main resolutions to be concerned about are 720p and 1080i. The "p" means progressive and "i" mean interlaced, in both resolutions every second has 60 frames of video.
Progressive resolution puts 60 full frames on the screen every second. Interlaced resolution puts 30 frames of only odd lines and then 30 frames of only even lines up every second. Some people find that the interlaced video causes flickering.
The 720p video resolution is 1280 X 720 pixels, which gives 921,600 total pixels and the 1080i video resolution is 1920 X 1080, which gives a huge 2,073,000 pixels.
It is personal choice as to which resolution you prefer, the best way of finding out is to go down to your local retailer and look for yourself.
The sound on HDTV will sound better than it did on your analog tv, some HDTV programs include Dolby Digital 5.1 surround sound, but you will need the relevant speakers to be able to take advantage of this.
You will have to buy a new HDTV. Some HDTVs come with built-in tuners, while others do not. The tuner converts the signal into something that your TV can recognize. HDTVs that do not come with a tuner are commonly called "HDTV Ready." An HDTV without a tuner is worthless.
It is possible to view HDTV on your pc, you can do this with ATi HDTV Wonder, it comes with its own antenna to pick up airborne HDTV signals, it also has inputs for cable and satellite signals. A benefit of this is that you can play and record any show you want on your computer.
Find more information at http://www.whathdtv.info