Lacto-Fermentation vs. Vinegar Pickling
Lacto-fermentation utilizes lactic acid bacteria (present on the skins of all fruits and vegetables) which converts natural sugars into lactic acid. The resulting acidic environment prevents any growth of harmful bacteria, making it one of the safest methods of food preservation.
The process of fermentation creates complex flavors and a diversity of beneficial bacteria (aka probiotics), while also enhancing its nutritional value.
Vinegar pickling is another form of food preservation but is acidified through directly adding vinegar. While also tasty in its own right, pickling in vinegar does not create probiotic bacteria.