Have you heard about persistent and runtime references? What do they mean? Why do SAP requires both persistent and runtime reference? How do they affect the way we program the workflow? If you have these questions in your mind then you should continue reading this blog. *What is persistent and runtime object references?* In workflow runtime, BOR objects are represented by SWC_OBJECT variables. However, in order to save object references in the database and transport them beyond session limits, persistent object reference variables of the ABAP type SWOTOBJID are used. *Why do SAP requires both persistent and runtime reference?* The workflow system stores object references in the container. These object references must be saved in the database whenever there is a context change (switch from one step to the next). This mechanism ensures the workflow can be restarted in case of server down or system crash using transaction SWPC. For this purpose, the workflow system converts the object references in the container from the runtime representation (blue areas) to the persistent representation (green areas) and back again, as required.