What is video interlacing?
When TVs display video, they display a new video frame at a rate that is faster than your eye can see (from 24 to 60 frames per second, depending on the TV and broadcast). Interlacing refers to whether each of those frames contains all of the lines of video for each frame or every other line. Interlaced signals take every other line from 2 frames of video (each lasting 1/60th of a second).