Apple Pay has several security features that make it useful for online payments.
When a card is added to Apple Pay, Apple says the original card number is not stored on its servers. Instead, the card issuer creates a device-specific Device Account Number that is stored in the Secure Element on the device.
When a payment takes place, Apple Pay uses this device-specific number together with a dynamic transaction security code rather than sending the merchant your actual card number.
Payments can also require biometric or passcode authentication. On compatible devices, that means another person cannot simply pick up an unlocked phone and approve an Apple Pay transaction without completing the required authentication.
Apple Pay security does not replace good account security. Use a unique Smooth Spins password, keep your device software updated and avoid letting another person access your casino account.