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).
Home cinema
By the mid-2010s, the Blu-ray Disc medium had become a common home media standard, and online video streaming sources such as Netflix and YouTube were offering a range of high definition content, including some 4K content (although various compression technologies are applied to make this streamed content feasible). The first 4K Blu-ray discs were released in 2016. By this point, 4K TVs and computer monitors were rapidly declining in price and increasing in prevalence, despite a lack of native 4K content. While many DSP systems existed, DTS-HD Master Audio remained the studio standard for lossless surround sound encoding on Blu-ray, with five or seven native discrete channels. High definition video projectors also continued to improve and decrease in price, relative to performance.