What is the role of Certificate Authorities (CA) in the digital certificate ecosystem, and how are they accredited and audited?

In the digital certificate ecosystem, Certificate Authorities (CA) play a crucial role in ensuring the trustworthiness and authenticity of issued digital certificates. A Certificate Authority is an entity that is responsible for issuing, managing, and revoking digital certificates. The CA is a trusted third-party that is authorized to verify the identity of certificate requesters and to issue digital certificates that bind an entity's identity to a public key. The CA uses a hierarchical model to issue digital certificates. The root CA is at the top of the hierarchy and is responsible for issuing digital certificates for intermediate CAs. The intermediate CAs are responsible for issuing digital certificates to end-users or other intermediate CAs. The end-user CAs are at the bottom of the hierarchy and issue digital certificates to....