Properly picked, as in preserved and can be stored ambient for extended periods, or "pickled" as sold in a supermarket where the small print says "keep refrigerated after opening"?

I have been told there is a huge difference between the two.

Qualify it as three types.

There are the fermented pickles

There are the pickles that get mixed with prefermented preservative (usually vinegar/salt) and pressure-canned

And then there are the pickles that get flash cooked or not cooked, mixed with preservative, and refrigerated for a limited time

Traditional "properly picked" also had to ve consumed after being open or stored cold. Once you open it, backterias can get in and spread.

There is some difference in taste, due to modern additiomal conservants and minor changes in receipta, but not all that much.