An HDMI 4K cable is a high-definition multimedia interface cable designed for transmitting 4K video and audio signals between devices. It supports 4K resolution (3840 x 2160 pixels), high refresh rates, HDR content, and various audio formats, delivering a top-quality viewing experience. HDMI 4K cables come in various lengths, offer backward compatibility, and may include optional features like Ethernet support. They are widely used to connect devices like 4K TVs, gaming consoles, Blu-ray players, and home theater systems for excellent picture and sound quality.