Android Pay is Google's latest attempt at a mobile payments network, replacing the old Google Wallet for most functions. Unlike Google Wallet did in the past, Android Pay is working in conjunction with banks and card issuers to make it super easy and secure to make payments with your credit cards in stores that have NFC payment terminals.
You can add credit and debit cards from many major banks — with more coming on board regularly — and card issuers, and once you have a card stored in Android Pay you can use it to pay at thousands of stores around the U.S. that accept Android Pay payments. Payments are quick and secure with a tokenized transaction, and you always have access to a history of transactions in the app. Because we're talking about access to your money here, you'll have to have a secure lock screen — fingerprint, pattern or PIN — on your phone, but that's best for everyone involved.
Android Pay can also store your loyalty and gift cards, so long as the app recognizes the program you're trying to add. Once you scan in or manually enter the loyalty or gift card, Android Pay can remind you to use it when you're at the store and instantly display a barcode for the merchant to scan so you can redeem your gift card balance or rack up rewards on a loyalty card.
Android Pay will also soon be the system that Google uses for in-app and online purchases, much in the way that Google Wallet (in the process of being renamed "Google Payments") currently does. Once the transition is complete, the Android Pay app will be your one-stop app for managing all of your payment methods and transaction history, whether they're in stores, in apps or online.
The two leftover features of Google Wallet not handled by Android Pay, person-to-person money transfers and the physical Wallet Card, carry on as they did before in a brand new Google Wallet app.