temporal resolution 
One of two possible ways to measure resolution in a video image; the other is spatial. Describes the amount of picture detail in a moving image, measured by the number of lines of resolution delivered over a given period of time. When an image moves rapidly, a 720p HDTV display will provide more picture information than a 1080i HDTV display because progressive scan produces twice as many frames in the same period of time as 1080i.