Workflow Versioning
Each workflow has a version history. Whenever a user makes a change to a workflow and saves the changes, a new version of the workflow is created. If a workflow is the default workflow, the changes are applicable even to the applications that are currently being processed by the earlier version of the workflow.
The Workflow History page lists all the versions of a workflow. Access the workflow history from the Version link on the Edit workflow page. For every version, you can view information about who made changes to the workflow and when. The latest version of a workflow is the active version. When you set a workflow as the default workflow, the latest or the active version of that workflow is considered as the default.