Balance ??

O.K., your audio signal is nothing but a wave (Dude!) with a positive cycle and a negative cycle... with me so far? Anyway, imajine spliting off the positive part and sending it to amplifier "A" and likewise sending the negative part to amp "B" (there are actually two amps for each channel which is why Balanced costs more). Onward... Now that you have the two halves isolated, you compare them to each other (the ground-wire value is used somehow as a reference. ever notice balanced interconects have 3 wires?) with the understanding that they should be complete opposites. If anything is found in common, it is assumed to be hum or noise of some kind and stopped dead in its tracks (does not get out of the amp). The result is a very quiet background for your music (Shazam)!

A balanced interface, whether low-level (interconnect) or high-level (amp output) means that there is no signal-ground reference. When a differential signal swings positive on one leg it is simultaneously swinging negative on the other leg. Ground is used only for shielding & does not carry either leg of the signal. Advantages are noise-immunity esp. with longer interconnects, and 6dB greater signal level than unbalanced. My full-balanced power amp. is dead quiet, compared to the very low-level noise of another amp which is unbalanced. Cost is a factor in balanced designs because there are more electronics involved. No need for any 'special' sources. Digital outputs (from a CD player) may be either unbal. or bal. just as analog connections can be done either way. An industry standard impedance for bal. is 600 ohm, vs. unbal. interfaces which vary.

...In layman's terms?

So, my follow up question is that if you have a choice between rca's and a balanced interconnect, then the balanced choice is a "no brainer", then, right ??