To get back to the basics and try to sumarize...
Electricity does "work" when a circuit is "complete" and power can flow form the source, thru the load, and back to the return.
"Ground" is a relative term for the return path. In general, dc circuits use the metal of the device as the ground. Ground can be neg or pos, but these days, 12 volt, negative ground vehicles are the standard.
A "short" (one of the most misused words in the english language) is an unintended parallel path to ground. It bypasses the intended load, and often results in the unintended flow of lots of current, resulting in heat, blown fuses, and sometime the letting out of the smoke. As everyone knows, electrical componants won't work if u let the smoke out. The smoke needs to stay in.
An open is a break in the circuit. It OPENS the loop, and current cannot flow and therefore no work can be done. Switches are "on purpose" opens, controlling the flow of power and determining if work will be done. Broken wires, burned connections, and other unintended opens are why many things don't work, and are sometimes terribly hard to find.