https://www.cnet.com/news/the-new-apple-card-wont-let-you-switch-from-iphone-to-android-probably-ever/

The world of payments isn't new to Apple, which launched Apple Pay, its mobile payment system, in 2014. But a full-fledged credit card, backed by Mastercard's payment network and Goldman Sachs, represents Apple's cannonball dive into banking in a way that will have ripple effects for Visa, Google Pay, Samsung Pay and every other digital payment player.

Everything from management to verifying transactions takes place on the iPhone.