In video resolutions, what does the 'i' in 1080i signify?

The 'i' in 1080i stands for "Interlaced." In interlaced video, the image is created by displaying alternating fields of lines—first the odd-numbered lines, then the even-numbered lines. This technique was commonly used in older television systems and can be advantageous for reducing bandwidth while providing a smooth appearance during motion.

Interlacing allows for the transmission of a full-resolution image at a lower bandwidth by splitting the image into two fields, effectively doubling the perceived frame rate without requiring twice the data. This can result in a flicker-free image while maintaining a reasonable resolution, which is critical for older CRT televisions. Understanding interlaced video is essential for professionals working in AV installation and broadcasting, as it relates to how various displays interpret and render video signals.