4K resolution
The term "2160p" could be applied to any format with a height of 2160 pixels, but it is most commonly used in reference to the 4K UHDTV resolution of 38402160 due to its association with the well-known 720p and 1080p HDTV formats. Although 38402160 is both a 4K resolution and a 2160p resolution, these terms cannot always be used interchangeably since not all 4K resolutions are 2160 pixels tall, and not all 2160p resolutions are ≈4000 pixels wide. However, some companies have begun using the term "4K" to describe devices with support for a 2160p resolution, even if it is not close to 4000 pixels wide. For example, many "4K" dash cams only support a resolution of 28802160 (4∶3); although this is a 2160p resolution, it is not a 4K resolution. Samsung also released a 51202160 (64∶27) TV, but marketed it as a "4K" TV despite its 5K-class resolution.
Apple TV
The 1st and 2nd generation Apple TV video output can be set to either 1080i or 1080p; however, this resolution is limited to the user interface and the viewing of photographs – all other content is simply upscaled to those resolutions. Those models cannot play 1080i or 1080p video content (e.g., HD camera video). The 3rd and 4th generation Apple TV support 1080p video content. The Apple TV 4K, as the name suggests, supports 4K resolutions and HDR, including Dolby Vision. 4K content from sources such as iTunes can be played on a compatible 4K television set.