The Light Side and Dark Side not being fleshed out after thirty five or so years after being introduced isn't pedantry. Sure, "Good vs Evil" worked for the first ten, or twenty years of the franchise, until they introduced Grey Jedi, Luke becoming evil on Tuesdays, and random Sith being Light Sith and there being Good Sith. So what is The Force? Is there a good side and a bad side, or is it just The Force?
For everyday purposes...Depends On The Writer.
Myself, I'm given to think that the Force and its dynamics actually works differently for each and every person. This manifests in unique abilities for certain Force users - some are given to Battle Meditation, some to Force Lightning (which is essentially
hating someone to death), some can pull off tricks no one has seen before (such as Kylo Ren freezing blaster bolts in mid-air).
The Dark Side, like the Force as a whole, works differently depending on the individual. For some it works like demonic possession, hollowing out their personality and replacing it with something bent on destruction for destruction's sake. For others (like poor Anakin Skywalker) it works as an emotional positive feedback loop that amplifies urges that normally wouldn't affect them.
And a select few (like Mace Windu, Kyle Katarn, or Cade Skywalker) can actually dip into the Dark Side as a reservoir of strength for judicious uses. However, it must be noted that a) this is dangerous unless you have the self-discipline of a Tibetan Monk, b) this is liable to result in long term psychological damage for the user even if it brings short term success, and c) if anyone could casually use it for good without repercussions, it would by definition not be the Dark Side.
Anyway, to get back to the original question...I don't think there's an answer, because the Force looks a bit different to each and every individual in the Galaxy thanks to things like worldview, formative events in their life, specifics in their training, and so on. Beyond a few specifics everyone can agree on (generated by life, permeates and binds all things, has Dark elements to it), the Force is
mysterious.