4K resolution
4K resolution, also called 4K, refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 38402160 (4K UHD) is the dominant 4K standard, whereas the movie projection industry uses 40962160 (DCI 4K).
Vudu
Movies are encoded in MPEG-4 video and Dolby Digital Plus audio. Vudu offers movies in three formats: standard-definition (480p and 480i), high-definition (1080p and 1080i) and ultra high-definition (2160p) or commonly known as UHD or 4k. Standard-definition movies are up-scaled to higher 1080i/p resolution and high-definition movies can be output at 1080p24. Audio is sourced in Dolby Digital Plus and output in Dolby Digital 5.1, with the option of stereo output. Audio is limited to stereo playback on HTPC/PC/Mac platforms. Users are able to adjust video to display in stretched, boxed, or zoomed format as well as adjusting overscan settings depending on their television format.