The specification has been updated to enable transmission of HDR formats, which provide enhanced picture quality by simultaneously enabling greater detail for both the dark and bright parts of an image. The HDR-related updates include references to CEA-861.3, CEA's recently published update of HDR Static Metadata Extensions

Connect a multimedia device to a display and support the latest HDMI features including 4K at 50/60 (2160p), up to 32 audio channels and wide angle theatrical 21:9 video aspect ratio

High definition audio/video technology continues to advance and the specification for HDMI equipment and cabling is occasionally modified to ensure broad compatibility and maximum performance.

HDMI delivers many new features:

• 4K@50/60, (2160p), which is four times the clarity of 1080p/60 video resolution
• Up to 32 audio channels for a multi-dimensional immersive audio experience
• Up to 1536kHz audio sample frequency for the highest audio fidelity
• Simultaneous delivery of dual video streams to multiple users on the same screen
• Simultaneous delivery of multi-stream audio to multiple users (up to four)
• Support for the wide angle theatrical 21:9 video aspect ratio
• Dynamic synchronization of video and audio streams\
• CEC extensions provide expanded command and control of consumer electronics devices through a single control point

4K
With the TV industry moving toward Ultra HD 4K, there needed to be more bandwidth in the connection to handle the future's higher resolutions and frame rates. HDMI supports 4K (2160p) up to 60fps. This allows full-resolution 4K 3D, along with higher-frame-rate 2D content, like home videos and computer games for PC.  

Bandwidth
HDMI increases the size of the pipe transmitting data from the source to display. This makes possible the increased frame rates at high resolutions. It also allows even more interesting lower-resolution images. HDMI supports dual video streams. There's also support for a 21:9 aspect ratio.

Notes:

• We manufacture High Speed HDMI Cables with Ethernet.  In accordance with HDMI rules, our cables are marketed in this manner with "High Speed HDMI Cable with Ethernet" marked on each cable jacket.
• Installing a cable supporting HDMI features does not necessarily give your existing devices with previous HDMI specifications the ability to experience 4K resolution, 3D, audio return or Ethernet.  The latest equipment supporting these desired HDMI features is required.
• HDMI cables are not hot-pluggable or hot-swappable for all devices.  Especially with PCs and projectors, you must first power off the devices completely, then plug in each new cable, then power on.  This enables the devices to learn the encoding in the cable and function properly and to your device's fullest potential.