Well, maybe it is important, because I'm trying to find one and those names are giving me other things.
I need a signal generator that I can clip to ONE wire and a detector that can detect the signal from up to six inches away.
Must not require power from the line being traced, nor require a circuit (most of the wires are open).
Would be nice if it is safe to use on "hot" wires. (One of the six is hot; if the device can't handle that, at least it will do the other five.)
Must be a "reasonable" price--I'd rather rip out the wall, eyeball it, and repair, than pay umpteen hundred dollars for a Progressive Electronics 521. I could build my own for less than that even if I paid myself $100 per hour!
I already paid fifty for one labeled "batteries not included" which made me think it would work. But only after opening it did I find that the sensor uses batteries and the transmitter only works if connected to both sides of a working line.