When you add a required input variable with Text data type or Record data type, the context key for the process is set automatically.
A context key gives a business reference to a process instance and can be used as an identifier for a process instance. When you look at the process instance in the Manage Process dashboard, you can quickly identify the process instance, and you can relate the process instance to the business use case. For example, an Approval Process that has a context key as HPD0002340 indicates that the Incident request HPD0002340 started the Approval Process.
If a process instance has multiple required input variables, the first input variable is used as the context key.
If a process does not contain any required process variables of data type Text or Record to start the process, a context key named instance is automatically added at the process run time. The context key is displayed in the Manage Processes dashboard.
If you have multiple required input variables and you delete the input variable that is used as the context key, the context key is assigned to a next suitable input variable.