This module concerns the way in which the workflow data is stored during the workflow execution and archived when the execution is completed. This is indeed a crucial module in a workflow solution.
While in Bonita v3 journal data (aka execution workflow data) and history data (aka archived data) where handled by different mechanism, in Nova Bonita we decided to unify them as the underlying essence of both is to handle workflow data. For that to be done, we created the concept of workflow record. A record is a minimal set of attributes describing a workflow entity execution. That means that each workflow entity related to the execution has its own associated record: instance record, task record, hook record...
Those records are recorded during the workflow execution and stored depending on the persistence service implementation (db, xml...). The Nova Bonita API will retrieve record data from the records storage and sent them back to the users (meaning that records also acts as value objects in Nova Bonita APIs).
As soon as a workflow instance is finished, a typical scenario would be (by default) to move instance related workflow data from the production environment to a history one. While the physical device and the data structure could changed from one workflow engine deployment to another (XML, BI database...), the internal format could remain the same (records). This is exactly what is happening in Nova Bonita, when archiving data the engine just move execution records from the production to the history environment without data transformation inbetween.