Short for
1080 interlaced,
where 1080 represents 1,080 vertical pixels. 1080i is one of two ATSC DTV
high-definition television standards.
The 1080i format creates an image with 1080 lines, each with 1920
pixels, so it
has a resolution of 1920 x 1080. 1080i is the minimum resolution necessary to
enjoy high-definition programming.
See also HDTV.