If you need more HDMI port on your TV, or diplay the same content on multiple TVs / monitors simultaneously, an HDMI switcher or HDMI splitter is enough. However, if you need to use multiple HDMI source devices and multiple high-definition display terminals at the same time, and want to be able to arbitrarily control the transmission of one or more HDMI signals to one or more display devices, the solution is HDMI matrix switch.