When you select a process task you specify which action will be run by the process step. The process task parameter templates are copied to the process step as parameters. This means that every process step that uses this process task can pass other parameter values. The original is not altered.
Compulsory parameters are immediately entered into the process step when the process task is selected. Then, you can enter any optional parameters individually. When a parameter is added, the value template is copied from the parameter template. Templates for parameter values are mostly predefined, for example, procedures that evaluate object UIDs and note them accordingly.