The video connector is what sits on the end of the video cable, and what plugs into the display and the computer. There are many different types of video connectors, from VGA to BNC.
The most common is probably right in front of you; the blue VGA cable that plugs your computers display into your computer. Since there are so many different types of connectors, we have built a database of which displays use what connector. For example, we know an Allen Bradley 1400e will always use a VGA connector.