The instance ID and instance number are two separate pieces of data.
The instance ID is the system-wide unique identifier that PerfectApps generates internally. The instance number is an app-specific sequential number that starts at 1 and is automatically incremented for each newly submitted app instance. The instance number is unique only to the app, but an instance ID is unique across the system.
You use the instance number to identify an app instance for one specific app type. Common examples would be for numbers visible to the app users such as: ticket numbers, invoice numbers and case numbers. Use this field when you want PerfectApps to manage sequential numbering.
Parent-Child apps use only the instance ID to maintain relationships between app instances.
See also: Creating and Managing Child Instances
Return to: Linking Apps and Using Parent-Child Relationships, Designing an App
