Apple Pay is a mobile payments service and digital wallet app that utilizes Near Field Communication (NFC) to initiate secure payment transactions between contactless payment terminals and Apple iOS devices like the iPhone 6, iPhone 6 Plus and Apple Watch. Processing Solutions Inc. encourages merchants to accept apple pay with contactless terminals. Apple pay stores the credit card information in a secure, protected environment. The payment information is tokenized and fully secure throughout the whole transaction.
Here is a Video on Apple Pay!
check out https://www.apple.com/apple-pay/ for even more detailed information.