Hi ASNeelima,
Please check out the documentation below that describes this key:
https://experienceleague.adobe.com/en/docs/campaign-standard/using/developing/about-custom-resources...
Identification keys
"Each resource created in Adobe Campaign must have at least one unique identification key.
When creating a custom resource, you have two options:
A combination of auto-generated key and internal custom key. This option is interesting if your system key is a composite key or not an integer. Integers will provide higher performances in big tables and joining with other tables.
Using the primary key as the external system primary key. This solution is usually preferred as it simplifies the approach to import and export data, with a consistent key between different systems.
Identification keys should not be used as a reference in workflows."
Regards,
Craig
