Balanced means both signals float with respect to ground. Single ended means that the negative side of the signal is circuit ground. Balanced usually has better noise rejection and therefore less noise....although the difference in home audio is subtle (in a studio where one is mixing all kinds of signals, with long signal paths, and often applying large gains then balanced circuitry is much preferred)
Why is this called balanced.... the idea is that both signal paths are nearly identical and therefore any stray noise is expected to affect both signal paths in an equal or balanced manner and thus will not affect the signal (difference between both balanced paths both affected by same stray noise = zero)
Why is this called balanced.... the idea is that both signal paths are nearly identical and therefore any stray noise is expected to affect both signal paths in an equal or balanced manner and thus will not affect the signal (difference between both balanced paths both affected by same stray noise = zero)