3D Secure is an additional layer of security for online credit and debit card transactions. It is designed to protect both the cardholder and the merchant by adding an extra step during the checkout process. When making a purchase, the cardholder is redirected to their card issuer’s website, where they are prompted to enter a unique password or code to verify their identity. This authentication process helps prevent unauthorized use of the card and reduces the risk of fraud. 3D Secure is widely used by e-commerce websites and provides peace of mind for both consumers and businesses when conducting online transactions.