What is Apple Pay, how does it work, and how do you set it up?

Apple Pay is a contactless payment technology for Apple devices. It was designed to move consumers away from physical wallets into a world where your debit and credit cards are on your iPhone or Apple Watch, allowing you to pay using your device instead of a card.

Source : https://www.pocket-lint.com/what-is-apple-pay-how-does-it-work-and-which-banks-support-it/