Question: what is the difference between sharepoint workflow 2010 and sharepoint workflow 2013?
Answer: Workflow, as far as I can tell at this point, is one of the most overhauled functionalities from SharePoint 2010 to SharePoint 2013. The first major difference is that it's no longer contained within SharePoint. Workflow is now handled by Windows Azure Workflow (WAW). ... You can host WAW on-premises just like SharePoint.