4 things HDMI does that have nothing to do with picture quality

HDMI cables are used to connect devices to your TV so you can hear and see things. It took a while, but over the past two decades or so, HDMI has become the dominant format for this, and the likes of composite and component cables have gone by the wayside. Those old formats still have a place when it comes to retro hardware such as game consoles and VCRs, so keep them around for that. For the most part, HDMI cables are all you need.