Although it looks the same as the earlier Apple TV 4K, the Apple TV 4K (2nd Gen, 2021, A12, Silver Siri Remote) has new internals with support for high-frame rate HDR (60 fps) with Dolby Vision when connected to a compatible television.
This Apple TV 4K is powered by a six core Apple A12 Bionic processor, has 3 GB of RAM, and is offered with either 32 GB or 64 GB of internal flash memory storage.
Connectivity includes HDMI 2.1, Gigabit Ethernet, 802.11ax Wi-Fi 6 with MIMO, low-power "Thread" networking support, and Bluetooth 5.0.
Perhaps most notably, this Apple TV 4K shipped with a much improved silver-colored "Siri Remote" with a touch-enabled "clickpad control that offers five-way navigation" and an outer ring that works as a "jog control" for quick scene selection. It also has a microphone for use with Siri. This Siri Remote also is compatible with the earlier Apple TV HD and Apple TV 4K (2017) and was available for purchase separately for US$59.