Overview:
PayPal Checkout with Smart Payment Buttons gives your buyers a simplified and secure checkout experience. PayPal intelligently presents the most relevant payment types to your shoppers, automatically, making it easier for them to complete their purchase using methods like Pay with Venmo, PayPal Credit, credit card payments, iDEAL, Bancontact, Sofort, and other payment types.
You can Try the Buttons on the PayPal website here, https://developer.paypal.com/docs/checkout/#try-the-buttons.
All the content above is take from the the PayPal Overview page here, https://developer.paypal.com/docs/checkout/.