Workflow activities
Workflow activities are the fundamental building block of workflows in SharePoint. For more information about workflow activities in SharePoint 2013, see SharePoint 2013 workflow fundamentals.
In SharePoint, workflow activities are derived from the Activity class, in the System.Workflow.ComponentModel namespace. In Nintex Workflow 2013 export (.nwp) file, custom workflow activities can be derived from the ProgressTrackingActivity class, which is in turn derived from the Activity class to ensure compatibility with SharePoint 2013. The ProgressTrackingActivity class provides additional support for Nintex-specific functionality, such as reporting. For more information about creating custom workflow activities, see Working with workflow activities.
Nintex Workflow 2013 can incorporate workflow activities derived from either the Activity class or the ProgressTrackingActivity class into custom workflow actions. For more information about creating custom workflow actions, see Creating workflow actions.