Actually, there are many types of process flow diagrams. Take a look at four of the most commonly used ones below:
Process charts – flow of a particular procedure;
Workflow diagrams – flow of documents and data;
Swimlane flowcharts – interactions of separate departments, employees, or processes;
Data flowcharts – processing of data.
If you dive deeper, you'll discover additional types like geographic, business processes modeling notation, SIPOC (supplier-input-process-output-customer), and many others.