The difference between HDMI2.0 and HDMI2.1 are as follows.
The biggest difference between HDMI2.0 and HDMI2.1 is bandwidth. The transmission bandwidth of HDMI2.0 is 18Gbps, while the bandwidth of HDMI2.1 is upgraded to 48Gbps. The most direct improvement brought by the increase in bandwidth is the increase in the amount of transmitted data.
HDMI2.0 can support up to 4K 60Hz video output, but HDMI2.0 does not support turning on HDR when the 4K 60Hz color space is RGB, and only supports turning on HDR in the YUV4:2:2 color mode. This means that a certain amount of picture color performance needs to be sacrificed in exchange for a higher refresh rate. And HDMI2.0 does not support the transmission of 8K video. And HDMI2.1 can support not only 4K 120Hz, but also 8K 60Hz.
In addition to higher bandwidth, HDMI 2.1 also supports VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode), which HDMI 2.0 does not support.
In addition, HDMI2.1 also supports dynamic HDR, while HDMI2.0 only supports static HDR.