Huh. I hadn't even heard of Discover.
[1]: https://en.wikipedia.org/wiki/Payment_Card_Industry_Data_Sec... [2]: https://www.pcisecuritystandards.org/
They did start the first payment card that wasn’t linked to a specific company (i.e. the American Airlines card).
Store accounts/cards have indeed been around significantly longer.
The distinction between a credit and a charge card is not that relevant in that context, in my view: For both, you spend an issuer’s money at unaffiliated merchants and pay the issuer back later.