4K resolution
As noted above, DCI 4K is 40962160, while 4K UHD is 38402160, producing a slight difference in aspect ratio rather than a significant difference in resolution. Traditional displays, such as LCD or OLED, are 3840 pixels across the screen, with each pixel being 1/3840th of the screen width. They do not overlap—if they did, they would suffer reduced detail. The diameter of each pixel is basically 1/3840th of the screen width or 1/2160th of the screen height - either gives the same size pixel. That 38402160 works out to 8.3 megapixels, the official resolution of 4K UHD (and therefore Blu-ray UHD discs).
4DX
4DX is a motion picture technology owned and developed by South Korean company CJ 4DPLEX, a part of the CJ Group. 4DX allows a motion picture presentation to be augmented with environmental effects such as seat motion, wind, rain, lights, and scents along with the standard video and audio. As such, theaters must be specially designed for and equipped with 4DX technology. The experience was introduced commercially in 2009 with the release of "Journey to the Center of the Earth" in Seoul, South Korea.