Definitions for "1080i"
The number 1080 stands for 1080 lines of vertical resolution, while the letter i stands for interlaced or non-progressive scan. 1080i is considered to be an HDTV video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels and a frame resolution of 1920 × 1080 or about 2.07 million pixels, and a field resolution of 1920 × 1080 / 2 (because it's interlaced) or about 1.04 million pixels. The field rate (not the frame rate) in hertz can be either implied by the context or specified after the letter i.