A Ticket Granting Server (TGS) is a key component of the Kerberos authentication protocol, which is used to secure network communications. The TGS issues tickets that allow users to access various services within a network after they have successfully authenticated themselves. This process helps ensure that only authorized users can access sensitive resources. When a user requests access to a service, the TGS verifies the user's identity and generates a service ticket. This ticket contains encrypted information that the user can present to the desired service, allowing for secure and efficient access without needing to repeatedly enter credentials.