what is the difference between 1080 i and 1080 p??

which is better, and is it much better than 720?

CRT is an acronym for Cathode Ray Tube - this is your run-of-the-mill tube TV. Not so good.

1080p is much better than 1080i. Though you probably won't be able to view that much of difference between 720p and 1080p unless you have a plasma TV larger than 61".

1080p means that there are 1,080 vertical lines of resolution. The "p" means that this picture has "Progressive Scan" technology which means a more frequently refreshed, clearer, picture for you.

1080i is basically the same except the "i" dictates that this is an interlaced image and isn't as frequently refreshed as 1080p.

Good luck and I hope this helps. When television was first introduced, the picture contained 525 lines per frame at 30 frames per second. Because of bandwidth limitations and picture tube limitations, those 525 lines were separated into two fields of 262.5 lines each; the first field contained the odd-numbered lines, and the second filled in the even-numbered lines. The fields were transmitted at 60 fields per second. This was supposed to be fast enough so that the eye would blend both fields together into one 525-line picture. This process is called interlacing, and is the "i" in 1080i. A picture displayed at 1080i shows half the lines first and the second half 1/60 second later.

With modern digital TV and fixed-pixel displays (LCD, plasma, DLP), there is no problem showing all of the picture at once. so the lines are displayed progressively (1,2,3,..etc) not leaving any out. This is progressive scan and is the "p" in 1080p