>>AUSTIN: Some of you may not know exactly what fermentation is, but I wanted to do a comparison to quick  pickling. 
Essentially, the differences are:
- With fermentation, we start off with a BRINE (which is a salt water solution).
- With quick pickling you already have the acid-- vinegar. Brine will become lactic acid as it ferments.
You've probably heard a lot about PROBIOTICS these days. 
Fermentation offers that; you're encouraging the good critters to form. 
When you eat the food, you're consuming those. They're added to your gut flora (the good bacteria).
With vinegar-based quick pickling, it's "dead", it's sterile.
The studies that I've read talk about how the fermenting critters add nutrients to the food. 
They can add enzymes, and some vitamins, and the probiotic aspects, they're donating themselves when you eat them. 
With quick pickling, not so much.
- SPEED, of course, is a key difference. Fermentations can be slow, depending on what it is you're fermenting.
And of course the last thing, which is why I got into this whole thing, is the FLAVOR. The flavor of lacto-fermented foods, is, I compare a “Mad Dog 20/20” or “Two-buck Chuck” [quick pickling] to a 40-year old Bordeaux [fermentation] in terms of its complexity. There are a lot more biological processes that are going on to enhance the food and add flavors (with fermentation). 
Whereas, not to disparage quick pickling, you can add whatever spices you want, but I think the flavor [compared to fermentation] is pretty flat.
