A Certificate Authority (CA) is an organization that issues digital certificates.
A digital certificate is the equivalent of an identity card and is used to assign a specific public key to a person or organization. This assignment is authenticated by the certification authority by providing it with its own digital signature.
The certificates contain "keys" and additional information used for authentication, encryption and decryption of sensitive or confidential data distributed over the Internet and other networks. Additional information includes, for example, lifetime, references to certificate revocation lists, etc., which are included in the certificate by the CA.
One of the tasks of a certification authority is to issue and verify such digital certificates. It is responsible for the provision, assignment and integrity assurance of the certificates it issues. This makes it an important part of the public key infrastructure.