Gentlemen - cables certainly make a difference.
The purpose of a cable is to transmit a signal while causing the least harm. Or, stated another way - with the highest fidelity.
Technically, how do cable transfer the signals? Explaining the many parts of a well designed and constructed cable requires a good technical understanding of electricity, metallurgy, dielectrics, electro-magnetics and physics. Each cable design and construction becomes critical for premium performance.
With a great system, set up in a treated room to perform optimally - it's easy to hear differences between cables.