[1] In the movie projection industry, Digital Cinema Initiatives is the dominant standard for 2K output and defines a 2K format with a resolution of 2048 × 1080.
Typically this is done at 2048 × 1556, but the exact dimensions vary based on the aspect ratio and size of the scan area.
This is the resolution of the 2K container format standardized by DCI in their Digital Cinema System Specification in 2005.
[2][3] The resolution of the encapsulated video content follows the SMPTE 428-1 standard,[6]: §3.2.1 which establishes the following resolutions for a 2K distribution:[7]: 6 However, the term 2K itself is generic, was not coined by DCI, and does not refer specifically to the DCI 2K standard.
[11][12] In consumer products, 2560 × 1440 (1440p) is sometimes referred to as 2K,[13] but it and similar formats are more traditionally categorized as 2.5K resolutions.