Discover
Networks & roles
A US-based card network operating a similar closed-loop model to Amex, with weaker international acceptance. European merchants typically route Discover via the Diners Club network (acquired by Discover) or through their existing Visa/Mastercard acquirer's Discover partnership.
In practice.
Discover matters mainly for US-facing merchants, and acceptance often comes bundled through your acquirer rather than negotiated directly. It also runs network alliances with several international schemes, so Discover acceptance can quietly include cards from partner networks.
Related terms: Visa · Mastercard · American Express
Networks & roles