Which of the following backends is NOT part of the core system connected to Vault?

The reason why deployment is not considered a core backend connected to Vault is that Vault primarily focuses on managing secrets and protecting sensitive data through its core functionalities, which include storage, authentication, and secret management.

The storage backend is where Vault stores its secrets and metadata securely, ensuring data durability and availability. The auth/identity backend handles user authentication and identity management, allowing Vault to verify entities who access secrets. The secret backend is responsible for managing various types of secrets, such as database credentials, API keys, and other sensitive information.

In contrast, deployment is not a core backend functionality within Vault; rather, it pertains to how Vault is implemented or integrated into an environment. While deployment strategies are essential for the operational aspects of managing Vault instances, they do not fall under the standard backend services that Vault offers for secrets and identity management. Therefore, identifying deployment as a non-core backend is accurate in the context of Vault’s functionality.