Digital certificates serve as electronic credentials that authenticate the identity of a website, server, or individual in digital transactions or communications. Rooted in public key cryptography, a digital certificate contains a public key and information about its owner, and it is issued by a trusted third-party entity known as a Certificate Authority (CA). When a user connects to a secure website, for example, the site presents a digital certificate to confirm its legitimacy. The user's web browser checks the certificate's validity, which includes ensuring that it was issued by a trusted CA and that it has not expired or been revoked. If the certificate is valid, secure communication can proceed using encrypted channels. Digital certificates are essential components in a wide range of security protocols, including SSL/TLS for secure web browsing, email encryption, and digital signatures for document authentication. They provide a foundation of trust on the internet, making it possible to conduct online transactions and share information securely.