PayPal can be used to checkout with your PayPal Account or with a Debit/Credit Card.
With a PayPal account. Proceed to PayPal from the checkout page.
Sign into PayPal and complete your order. (PayPal sign in page shown below)
To pay with a Debit or Credit Card and NO PayPal Account:
No PayPal account. Proceed to PayPal from the checkout page.
You will come to the PayPal sign in page pictured below. Instead of signing into PayPal click the Pay with Debit or Credit Card button below the Log In button (AREA INDICATED BELOW). No PayPal sign in required. Complete your information to pay with a Debit or Credit Card and complete your order.