The need to "split" an HDMI signal is quite common. In residential applications, splitters are often used for sending a single cable box to multiple displays. In office applications, splitters are often used for sending a single computer to multiple monitors. In education applications, splitters are often used to send a video source to both a desktop monitor and a ceiling mounted projector. There are lots of use patterns, and they all revolve around the need to take a single HDMI source and send it to multiple destinations.
The TL-DA12-HD2 splits a single source to two destinations (typically displays or projectors). A built-in amplification circuit ensures performance for higher resolutions: 1080p, 4K@30, and 4K@60, and longer cable lengths.