Data Rule has criteria/set of criteria that could spot sensitivity in data and defining a rule that classifies data as sensitive is the foremost step in achieving data security.
Data Rule is a gateway to adhere to compliance standards like HIPAA, PCI DSS, and GDPR using predefined criteria that encompass relevant criteria. You can also create your organization-specific Data Rule by leveraging custom criteria per your organizations' requirements.
Refer here to know more about achieving compliance through data rules.