The Payment Card Industry Data Security Standard (PCI DSS) is the worldwide standard set up to protect cardholder data and help businesses process card payments securely. It is issued, administered and managed by the Payment Card Industry Security Standards Council (PCI SSC). Its compliance is enforced by the major payment card brands like Visa, MasterCard, American Express, Discover and JCB., and also includes Bancontact and Maestro in the scope.
All companies that accept, process, store or transmit credit cards and debit cards information need to comply with PCI DSS to protect cardholder data.
3D Secure (also referred to as 3D secure authentication or 3DS) is a fraud prevention protocol developed by EMVCo to secure card payments by adding an authentication process before making purchases online.
When a payment is processed using the additional security layer of 3DS, the card holder is required to authenticate himself by providing an additional identification key.
Additional information can be found here.