Which task is primarily used to send notifications in a workflow?

The task that is primarily used to send notifications in a workflow is the notification task. This task is specifically designed for sending messages or alerts to users, keeping them informed about critical updates or actions that require their attention within the workflow. It allows automation of communication, which is essential for maintaining connectivity and ensuring that participants are aware of their responsibilities without manual intervention.

While other tasks like service tasks, user input tasks, and script tasks are important components of a workflow, they serve different functions. Service tasks are typically used for backend processes, user input tasks gather data or action from users, and script tasks execute code or scripts. None of these tasks are inherently designed to handle notification messaging in the way that the notification task does. Thus, the notification task is the correct choice for sending notifications effectively within the workflow.