(CA) Certificate Authority

A Certificate Authority (CA) is an entity responsible for issuing and managing digital certificates that are used to secure internet transactions and authenticate the identity of the parties involved. Digital certificates are an essential component of secure internet communication and are used to establish trust between parties. A CA operates as a trusted third-party that verifies the identity of entities requesting a digital certificate and then issues a certificate that includes the public key of the entity along with its identity information. This information is then used to verify the authenticity of the entity during online transactions, such as secure web browsing, email, or file transfers.

https://www.thesslstore.com/blog/root-certificates-intermediate/