SpringHeeledJack
Oh dear. Sorry.
At least you're not alone, I had great difficulty the other day explaining to a Windows user why the default IPv6 settings on their machine was causing problems on their local IPv4 network.
Its one of those frustrations of computing that most seemingly simple concepts are actually composed of a number of technical elements, which makes plain English descriptions difficult.
Someone could get very rich if they figured out a way to describe techy stuff in plain English. I've looked at things like the "For Dummies" guide and they're not really that plain English either.
Oh well... maybe next time I'll use an illustration instead.... pictures & thousand words as they say !