Paying with Apple Pay is safer than using a plastic physical card. Each transaction requires authentication with Face ID, Touch ID, or a code. Your identity is not shared with the merchant, and actual card numbers are not stored on your device or on Apple's servers.
When you pay in stores, neither Apple nor your device is sending actual card numbers to the merchants. When you pay on apps or websites, the seller only receives information that you consent to provide to fulfill your order, such as your name, email address, billing address, and shipping address.
Apple Pay keeps anonymous information about the transaction, such as the approximate amount of your purchase. This information cannot be associated with you and never discloses what you have purchased.
Apps that use Apple Pay must adhere to the privacy policies.