2K

2K is a high-definition video resolution standard that allows slightly higher resolution than 1080p signals - up to 2048x1080.

2K refers to horizontal resolution, in contrast to standard digital TV resolutions which are stated in vertical lines.  If 1080p has 1080 lines of vertical resolution (1920x1080), 2K has the same number of lines of vertical resolution with slightly more pixels of horizontal resolution (typically 2048x1080).

2K is mostly used to rate digital cinema formats, since the Digital Cinema Initiative (DCI) backed by the major Hollywood studios uses a 17:9 aspect ratio that better aligns with several of 35mm and 70mm films formats used to shoot and project movies.