Spirit,
It's okay to ask something without denigrating yourself

We were all newbies once and I still know less than I will in another couple years. Partly, because I'm dense

Shielding usually means there is a length of copper or aluminum (foil, mesh or otherwise) running along the length of the wire (under the cover, so you typically don't see it). Copper and aluminum have slightly differing properties at different frequencies, but both work to shield your wire/cable from picking up Electro-Magnetic Interference (all of your power supplies, for instance, radiate this...also called EMI) and Radio Frequency Interference (every radio and TV station casue this...also called RFI).
There is more noise (in the form of RFI and EMI)
shielded from what is often a very nice (virtual)antenna...6' of power cord. I find that unshielded sound a bit better...but only because I live in the 'burbs now. When I lived in Washington DC pre-2002, and was 150 yards from the main TV and Radio towers, I definitely needed shielded power cords.
If you receive good picture quality and terriffic FM signals where you live - you probably will appreciate the shielding. If you don't pick up any TV unless it's cable, etc. and FM is spotty - you may be better off with unshielded
