A certificate authority (CA) is a trusted entity that issues and manages digital certificates for secure communication over the internet. A digital certificate is a document that contains the public key and the identity of the owner of the key. A CA impacts security by validating the domain identity of the SSL certificate, which is a type of digital certificate that enables encrypted communication between a web server and a web browser. The CA verifies that the domain name in the certificate matches the domain name of the web server, and signs the certificate with its own private key. The web browser can then verify the signature of the CA and trust the identity of the web server. References := Cisco Cybersecurity Operations Fundamentals, Module 2: Security Monitoring, Lesson 2.3: Cryptography and PKI, Topic 2.3.2: Public Key InfrastructureReference: https://en.wikipedia.org/wiki/Certificate_authority

Digital certificates are electronic documents that use public key cryptography to verify the identity and authenticity of the sender and the receiver of encrypted communications. Digital certificates are issued and signed by trusted entities called certificate authorities (CAs), and they contain information such as the public key, the name, and the expiration date of the certificate. Digital certificates enable network security devices to decrypt perimeter traffic and inspect it for command and control communications or other malicious activity.
References := Understanding Cisco Cybersecurity Operations Fundamentals (CBROPS) - Cisco, page 51.