witch is better 1080i or 1080p what is difference between them?

1080p provides a smoother picture, but 1080i uses only half the bandwidth (i.e. 4 seconds of 1080i content is the same amount of data as 2 seconds of 1080p content).

1080p means all 1,080 lines are drawn in order (or at once), whereas 1080i means the odd numbered lines (every other line) is drawn on the screen in half as much time, then the other lines (the even numbered ones) are drawn to fill in the spaces. So 1080p will look smoother.

One other thing: some early CRT HDTVs, especially non-widescreen 4:3 models, were 1080i models that had 1,080 lines, but their horizontal resolution (width of each line in pixels) was less than 1,920, so it's actually fewer pixels than 1080p or true 1080i (1080x1920).

So 1080p is better in terms of picture quality, but uses more bandwidth and is more likely to cause flicker on a CRT set.

I see this question every single day. Then a bunch of people jump in to tell you that 1080p is better, blah, blah blah.

What most people fail to mention is that no flat panels actually display a 1080i picture so your question almost becomes meaningless.

If you have a 720p TV, it will down convert anything above 720 lines, back down to 720. If you have a 1080p set, it upconverts broadcast 1080i from over the air, HD cable or SAT to 1080p, it will never display a interlaced image.

flat panels are all progressive but people get confused because TV makers keep putting that 1080i moniker on their cheap 720p sets when it just describes compatibility.

1080p only exists on BluRay right now. There is some infant gear being put into place (ESPN) to accommodate 1080p for broadcast, but its not there yet. DirecTV claims 1080p movie broadcasts, but I kind of question the validity of that myself.

Broadcast TV is either 720p or 1080i right now. And its likely to remain that way for the foreseeable future. Mainly because of costs associated with having to upgrade to accommodate 1080p over broadcast systems.

As for the difference though, think of your TV as broken down into 1 pixel high rows. In 1080p, each time the image on the screen is scanned (drawn), every single one of those rows is drawn. You get what is called a full/complete frame. That's how progressive, "p", systems work.

But in an interlaced, "i", system, each time the screen is scanned, every other row is drawn. This creates what is called a field. 2 consecutive fields make up a completed frame. Because of the speed at which these fields are played back (1/60th of a second), and the nature of the human eye, the resulting image still comes out looking like a complete image for you. But because each scanned image is only half of the rows, it requires half the bandwidth to transmit (so why broadcasters like it).

1080i is used typically in drama/comedy or such TV series. 720p is used typically for sports. Its a lower resolution, but because its progressive, it can do a better job delivering a crisp image for fast moving object. And because its a lower resolution, it requires less bandwidth (so hence they can transmit a progressive image now).