For an overview about the concept and workflow tutorials please check the main Workflow article.
Sense/Net workflow types
Content workflows are related to one particular content. For example an Approval workflow is started on a document. This Related Content must be available before the workflow starts and during the whole life cycle of the workflow.
To make a workflow a content workflow you have to set the ContentWorkflow field of the Workflow Definition to True.
From version 6.3 there is a separate field (Assignable to content list) that determines if users can assign the workflow to a content list. You can create content workflows that are not related to any content list (e.g. the document preview generator workflow).
Standalone workflows can be used in the whole portal, wherever the administrator wants a workflow entry point. They are not related to a particular content, for example because it does not exist yet (like the user content in the registration process) or there are more than one content that the workflow is related to.