HDMI (High-Definition Multimedia Interface) is the dominant audio/video standard for connecting TVs, monitors, and projectors. Current HDMI 2.1 supports 4K 120Hz, 8K 60Hz, and eARC audio.
HDMI evolution and specs: HDMI 1.4: 4K 30Hz, 3D support, introduced in 2009. HDMI 2.0: 4K 60Hz, introduced 2013, standard for 2013–2021 devices. HDMI 2.1: 4K 120Hz, 8K 60Hz, 10 Gbps+ bandwidth, variable refresh rate (VRR), eARC. Rolled out 2017+, majority adoption 2021+. HDMI 2.1a/2.1b: 8K 120Hz, introduced 2021, rare in consumer devices.
Connector types: Type A (standard, 19-pin) on TVs and laptops, Type C (mini) on some tablets, Type D (micro) on small devices. Adapters to USB-C or DisplayPort are common on newer laptops.
Advantages over USB-C: established ARC (audio return channel) for soundbars, wider device compatibility, longer cable distances (up to 50 m passive). Disadvantages: bulkier than USB-C, not reversible.
The HDMI cable itself doesn't determine quality — all HDMI 2.1 cables deliver the same signal. "Premium" cables are marketing; any certified HDMI 2.1 cable works fine.