HDMI is now the most common format for AV signals in nearly all consumer, and even many professional, products. However, HDMI was primarily designed for domestic use and was never intended to run over distances of say 10m+.
In circumstances where longer cable runs are required, manufacturers had in the past created their own proprietary methods of sending HDMI over longer distances using CAT5/6 cable, but these were not compatible with each other.
HDBaseT is a common standard that has been widely adopted by many manufacturers for sending HDMI over longer distances (i.e. 10m-100m). It allows for compatibility between different manufacturers' hardware and gives buyers more certainty and future-proofing. It can usually carry HD video, stereo audio, control signals, LAN and power (PoH).
HDBaseT-Lite is a reduced version of HDBaseT that runs up to around 60m and carries HD video and stereo audio.
For more information visit: hdbaset.org