Multiple displays from one source
A video splitter for digital signals such as HDMI or DVI will distribute the video and audio signals from a single source to multiple displays without losing quality. For example you could display a video from a DVD player or PC on both a monitor and a projector simultaneously. To ensure that no quality is lost the devices are active (requiring a power supply) which means they are able to reproduce the signal rather than just splitting the original signal. Different splitters are capable of supporting higher resolutions such as HD and 4K.