Learn about the workflow actions that are available for workflow authoring in SharePoint Designer 2013, and the workflow activity classes that are available to workflow developers using Visual Studio 2012.
Workflow activities and actions
Workflow activities represent the code-level objects that handle method calls to the various APIs that drive workflow behaviors. You interact with workflow activities in code, using or another development environment.
For a list of available activities, see Workflow activity classes in SharePoint.
On the other hand, workflow actions are wrapper objects that encapsulate these underlying activities and present them in a user-friendly form in SharePoint Designer. You interact with workflow actions in SharePoint Designer.
For a list of available workflow actions, see Workflow actions quick reference (SharePoint Workflow platform) and Workflow actions available using the workflow interop bridge.
Windows Workflow Foundation 4.0 activities
Although the SharePoint platform and infrastructure provide you with specially crafted activity classes for creating custom SharePoint workflows, you can also use any of the activities that are provided by Windows Workflow Foundation (WF) 4.0. These WF 4.0 activity classes are available in the Microsoft .NET Framework 4 in the System.Activities.Statements namespace.
The WF 4.0 activity classes provide some useful features that you may not find in the SharePoint activity class library. For example, WF 4.0 includes the If class, which allows you to create conditional activities. Additionally, you can use the System.ServiceModel.Activities.Send activity to connect to web services.