HDMI, or High-Definition Multimedia Interface, is a standard for transmitting high-quality audio and video signals between devices. It connects various types of equipment, such as TVs, computers, gaming consoles, and projectors, using a single cable. HDMI supports both standard and high-definition video, as well as multi-channel audio, making it a popular choice for home entertainment systems. The interface has evolved over time, with newer versions offering features like 4K video support, enhanced audio formats, and Ethernet connectivity.