Users can add their PayPal accounts to Samsung Pay and use their PayPal wallet anywhere Samsung Pay is accepted. And because it uses proprietary MST (Magnetic Secure Transmission) technology, which allows you to use Samsung Pay at terminals that don't accept NFC, it's accepted more places than any other mobile payment platform. Merchants will also be able to accept Samsung Pay online through PayPal's Braintree.
Using PayPal wallet with Samsung Pay is only currently available in the United States. However, Samsung is working on expanding PayPal wallet support to the 18 other markets it serves, including Spain, South Korea, China and India, soon.
This is a good move for PayPal as well. The service has been moving more and more into mobile payment methods. With these integrations, you may soon be able to use your PayPal account just like a real bank account.