1. A network hub is a device to take multiple computers/devices, and join them together into a network. They are a form of repeater rather than a server. Hubs are not to be confuse with "Switches" or "Routers" as all they do is repeat the signals to everyone connected. Hubs form a "collision domain", basically repeating out to all nodes all information that comes in. Because of this, frames are routinely because they run into each other on the line. This causes a good amount of latency in the network. Hubs should never be used for any type of show control.
2. Hub, aka Hub Electric Co., was a manufacturer of stage lighting fixtures and controls from the 1950s through the mid-1970s. Their assets were purchased by Vara-Light/Dimatronics of 6207 Commercial Rd, Crystal Lake, IL 60014; (815)455-4400.