Question: what is the difference between 2 hdmi and 3 hdmi?
Answer: Resolution. HDMI 2.1 allows for higher resolutions at higher frame rates than before. With HDMI 2.0b we could enjoy a maximum of 4K resolution at a maximum frame rate of 60Hz. With HDMI 2.1, we can get 4K at 120Hz, 8K at 60Hz, and right up to 10K resolution for industrial and commercial applications.