What type of integration mechanism involves predefined authentication methods?

The correct choice refers to predefined plugins as integration mechanisms that include authentication methods that are already defined within the system. Predefined plugins streamline the integration process by providing ready-to-use solutions that have built-in protocols, allowing for the quick setup of secure communication between systems. These plugins generally encapsulate the complexity of various integrations and ensure that both sides adhere to established security standards and authentication practices.

This approach contrasts with other types of integrations. Web services, while often secure, typically require independent setup and configuration of authentication protocols. Messaging integrations may also involve custom security implementations. Batch processes generally do not focus on ongoing or real-time authentication, as they operate in fixed intervals and often do not require continuous authentication checks. Thus, predefined plugins stand out for their readiness and adherence to security protocols without needing extensive customization or development.