A Certificate Authority (CA) is an entity that issues digital certificates that are used to verify the identity of a person or organization online. The purpose of a CA is to provide a secure and trusted way for parties to exchange information over the internet.
For example, a website may use a CA to issue digital certificates that authenticate the identity of its customers. This helps to ensure that the website is secure and that customers can trust the website they are interacting with. Similarly, a CA can be used to issue digital certificates for secure email and other applications.