HDMI stands for High Definition Multimedia Interface, which is an interface used for the transmission of high quality audio and video data.
If you are wondering why HDMI cable is better than the analog cable, the answer is that, unlike the analog cable, HDMI is a digital uncompressed source. The difference is simple: the analog cables takes a digital signal and convert it into a weaker analog signal which is then transmitted to your TV. This signal is then converted again to digital, for playback on the screen. With these multiple conversions of the original signal, the clarity of the image is lost, the result being less clear picture and low quality sound. An HDMI cable retains the original digital signal, eliminating the need for conversion, the result being a clear and very clean image, as well as sound at the highest quality.
The HDMI cable can be used on PC, DVD player, console etc.
Although it looks very similar with a USB cable, it has 19 wires inside. What is different about this cable is that it can transmit content with a bandwidth of 10.2 Gbps. Its capacity is remarkable if we consider that it is twice bigger than the necessary to transmit multiple audio or video channels. The conclusion is that, obviously, this type of cable is going to be used a long time from now.