A video converter simply converts one format of video signal to another. A common example is converting an analog signal to a digital signal (or VGA to DVI). Other common conversions are S-Video to VGA (Luminance and Chrominance to RGBHV) and VGA to HDMI so that you can display your PC output on your new HDTV.
A video extender usually extends a video signal over Cat5e cable. A transmitter is located close to the video source and a receiver is placed next to the video display. The difference between a video extender and a video booster is, a booster is usually placed inline between the video source and video display. A booster usually requires power and works by regenerating the video signal.
A video matrix is a cross between a video splitter and a video switch. A video matrix allows multiple video inputs to be displayed on multiple video displays. Common configurations are: 2 inputs, 2 outputs and 2 inputs, 4 outputs.
Video Splitter (Video Distributor)
Video splitters (also known as video distributors) duplicate a video signal and output it to 2, 4, 8 or even 16 video displays.
Video Switch (Video Selector)
A video switch (also known as a video selector) does the exact opposite if a video splitter. A video switch allows multiple inputs to be displayed on a single monitor/projector.