HDMI standards refer to a set of specifications for transmitting high-definition audio and video signals between devices. The most common versions include HDMI 1.4, HDMI 2.0, and HDMI 2.1, each offering improvements in bandwidth, resolution, and features. For example, HDMI 2.1 supports higher resolutions like 8K and advanced features such as Variable Refresh Rate. These standards ensure compatibility between devices like televisions, gaming consoles, and Blu-ray players. Each version is designed to enhance the user experience by providing better picture quality and sound, making it easier to connect and enjoy multimedia content across various platforms.