When going through the ordering and checkout process on this website you can choose to either pay immediately by credit or debit card at the secure PayPal site, or pay by other means such as cheque, BACs etc.

Online credit and debit card payments are processed offsite at the secure PayPal website - we never see you card details.
From the PayPal site:
1. You can either pay via your PayPal account, or
2. You do not need a PayPal account to pay. You can pay directly via credit or debit card - to do this click on the Continue link on the PayPal page where it says:
Don't have a PayPal account?
Use your credit card or bank account (where available). Continue