Difference 1080i and 1080p?

1080i and 1080p are both High Definition display formats for HDTVs. 1080i and 1080p signals actually contain the same information. Both 1080i and 1080p represent a 1920x1080 pixel resolution (1,920 pixels across the screen by 1,080 pixels down the screen). The difference between 1080i and 1080p is in the way the signal is sent from a source component or displayed on an HDTV screen.
In 1080i each frame of video is sent or displayed in alternative fields. The fields in 1080i are composed of 540 rows of pixels or lines of pixels running from the top to the bottom of the screen, with the odd fields displayed first and the even fields displayed second. Together, both fields create a full frame, made up of all 1,080 pixel rows or lines, every 30th of a second.
In 1080p, each frame of video is sent or displayed progressively. This means that both the odd and even fields (all 1,080 pixel rows or pixel lines) that make up the full frame are displayed together. This results in a smoother looking image, with less motion artifacts and jagged edges.

1080p can also be displayed (Depending on the video processing used) as a 1080p/60 (Most common), 1080p/30, or in 1080p/24 formats.
1080p/60 is essentially the same frame repeated twice every 30th of a second. (Enhanced video frame rate.)
1080p/30 is the same frame displayed once every 30th of a second. (Standard live or recorded video frame rate.)
1080p/24 is the same frame displayed every 24th of a second (Standard motion picture film frame rate.)