We know that Magento saves a logged-in customer's shopping cart items in the database for a very long time (if not forever).
Then what's this "Persistent Shopping Cart" option for? What difference does it make? What's its advantage?
It saves the quote ID in a long living cookie (
persistent_shopping_cart) so that even when the session expires, guest customers maintain their carts.
I may be wrong, but it might just be a renaming (aka branding) of the existing functionality.