Oh that’s easy enough. If they need a PIN it’s actually being run as a debit card over the debit card network. Otherwise it’s being run as a “check card” over the credit card network (with higher fees and better consumer protections). It’s just backed with money instead of a line of credit.
> Why do online stores need my name and address, but IRL ones do not?
IRL stores have access to the actual card (with your name) and having this artifact present makes it much less likely that you are a fraudulent fraudster committing fraud, so the processors are willing to take it.
> How can restaurants swipe my card now and charge me later?
the good news is if the store ever defrauds you, everyone knows where to find the store! Unlike fraudsters making purchases.