I have a vocabulary question.

I'm not entirely sure that Tutordennis' 2nd sentence is entirely wrong. Pairs in cables and IC's may be able to be like shoes sometimes, like scissors at others. From a prescriptivist point of view, there would be no ambiguity, but I think I have heard of some speaking of a pair of interconnects when only one wire was in hand? Too bad the OED online is subscription only.

Thanks! I feel better.

A 'pair' of interconnects mean two cables which run between two componants.
The same is true of speaker cable. One pair of speaker cable couples the amp and the pair of speakers.

Every signal path consists of forward and return paths.

A power cord has the plug with two or three prongs. Two of them are signal ones and one is ground. Signal ones are hot and newtral. Hot is forward and newtral is return.

A speaker wire consists of two wires either terminated or unterminated to be hooked up with speaker binding posts one of wire is forward and the other is return. Make sure keep connection in synch with power amplifier binding posts using color coding.
You need a pair of speaker wires if you have 2-ch system and more speaker wires if you have more than 2 channels.

An interconnect cable consists of one or two signal wires and ground. In case with balanced thre-wire interconnect you have one signal wire forward, one signal wire return and one ground wire. In case with unbalanced two-wire interconnect you have signal forward and ground return.
For every channel you will need one such interconnect cable.

Interconnects: cables used for interconnecting one component to another. usually RCA termination or XLR balanced connection. Usually sold in pairs unless noted length indicated in meter lengths
Speaker cables: usually sold in pairs and and sold in lengths indicated in feet in most cases. Terminations will vary from stranded(non-terminated) to spade lugs, bananas or pins