This is referred to as establishing an “HDMI handshake”. High-bandwidth Digital Copyright Protection requires that all HDMI connected components be able to recognize and communicate with each other.
However, there is another purpose, copyright-protection (known as HDCP). One purpose of HDMI is to simplify connecting all your components together by using one cable for both audio and video. HDMI is now the main type of connection used in home theater setups that include HDTVs, video projectors, Blu-ray Disc players, home theater receivers, network media players, and even cable/satellite boxes.
