Final answer:
The CAC/PIV card contains certificates for accessing restricted websites and for two-factor authentication. It's a security measure used by government agencies to protect sensitive information and is not intended for personal social media or entertainment purposes.
Step-by-step explanation:
The CAC (Common Access Card) or PIV (Personal Identity Verification) card is a controlled item that is mainly used within the United States Department of Defense and other federal agencies to ensure secure access to information and facilities.
These smart cards contain digital certificates for accessing restricted websites and perform two-factor authentication, which dramatically enhances online security for individuals by requiring two forms of identification before access is granted to sensitive resources. They are not used for personal accounts such as social media nor for personal entertainment. In the broader context of online privacy and security, measures like the implementation of two-factor authentication are essential to protect against unauthorized access and potential security breaches.