HDMI stands for High-Definition Multimedia Interface, it’s a video standard that has an interface through a cable that receives the same name, HDMI cable, and that allows input devices to be connected with the of output integrating high-definition video and HD audio of up to 8 channels in the same cable, all the video and audio information is sent without compression. HDMI was created by industry majors in both consumer appliances and film and TV, including Panasonic, Philips, Sony, Toshiba, Universal, Warner Bros, Fox, and Disney.
HDMI in its first version was introduced at the end of the year 2002 that supported almost 5 Gbit/s, the equivalent of a resolution of 1080p 60Hz with 8-channel audio at 192 kHz. As video and audio standards have evolved to include more and more quality media, HDMI has had to be updated early enough to make them compatible between playback and output devices, so in version 1.4 of HDMI it is already included support for 3D video and an Ethernet connection built into the cable itself with a speed of 100 Mbit /s.
The HDMI cable has 19 pins, of which 12 are for the TMDS channel, which is responsible for transporting audio, video, and auxiliary data, one for the CEC channel, which is used for remote control functions, and the others are divided into various functions more like auto detection when connecting cable, 5v voltage etc.