In September of 2017, Apple introduced the Apple TV 4K, its first update to the set-top box since 2015. There are two key technologies at the heart of the fifth-generation Apple TV: 4K and HDR, both of which bring cinematic quality to everything you watch on the set-top box.
4K support brings incredible detail to the Apple TV with four times the number of pixels as HD. 4K resolution is defined as 3840 x 2160, while HD is 1920 x 1080. While the 4K Apple TV offers improved resolution, its support for high dynamic range (HDR) is perhaps even more important. HDR brings richer, more vibrant colors and supports a wider range of colors.
As iTunes chief Eddy Cue said on stage when introducing the Apple TV 4K, 4K is about the number of pixels, but HDR is about better pixels. Apple TV 4K supports both the HDR10 industry standard and Dolby Vision, a higher-quality version of HDR with even better color.
The Apple TV 4K is meant to be paired with television that supports both 4K and HDR technology. Without an accompanying 4K television, the Apple TV 4K experience won't be the same. To get the most out of the Apple TV 4K, 4K content is also required.
Apple is offering 4K movies through its iTunes Store, and 4K content is also available through Netflix, Amazon Prime Video, and other streaming services. 4K content from YouTube isn't supported, though, as it uses an incompatible format.
The tvOS interface has been redone in 4K with sharper text, and more vibrant images. Videos captured on the iPhone can be viewed in 4K on the Apple TV, and all of the Apple TV's animated video screensavers have been remastered in 4K. It supports apps like Apple Music and allows the Apple TV to serve as a HomeKit hub and an access point for controlling all of the connected devices in your home.
Inside, the Apple TV 4K is equipped with an A10X Fusion chip, the same chip used in the 2017 iPad Pro models. The Apple TV is twice as fast when it comes to CPU performance and four times as fast when it comes to GPU performance, enabling a whole new class of apps and games.
There have been no design changes to the Apple TV, so it continues to look like a simple black box that plugs into a television using an HDMI cable. There's a Gigabit ethernet port included, and the USB-C port that was on the previous device has been removed.