Whenever an error or failure is encountered within a workflow, there are multiple options for handling the outcome of that result. The simplest method for dealing with errors during a workflow is to retry tasks from the point of failure, but there are more advanced options as well.
If an error occurs during a workflow, a task or workflow creator also has the ability to leverage rollback actions as well. Tasks can be programmed to have specific details for how to perform a rollback, which means that the task understands how to undo any action which was performed.
Evaluating for failures is performed at the task level, and each rollback is handled at the individual task level, which allows a workflow to be stopped and rolled back at any specific task if the rollback action has been defined.
The definition of error & rollback at the task level is intended to prevent a workflow from encountering an error and not halting at a good point, not leaving an environment in an unknown or non-functioning state, nor having a workflow partially completed where it cannot be exited and executed again due to partial completion.