In Microsoft Purview, Sensitivity labels are the feature designed to let users identify and classify content that should be protected. Microsoft’s guidance explains that sensitivity labels “enable you to classify and protect your organization ' s data while ensuring that user productivity and collaboration aren ' t hindered.” Users can manually choose a label in Office apps and services to indicate the data’s sensitivity; as Microsoft notes, labels “can be applied by users or automatically,” and the label “persists with the content in its metadata.” Once identified with a label, protection settings can be enforced, including “encryption, content marking (headers, footers, watermarks), and access restrictions based on the label.”

By comparison, Data Loss Prevention (DLP) focuses on “monitoring and blocking the unintentional sharing of sensitive information” based on policy—DLP enforces handling rules after data is identified, rather than providing the user-centric classification mechanism. Insider Risk addresses “risky user activities and insider data security scenarios,” and eDiscovery is used to “find, preserve, collect, and review content for investigations or litigation.” Therefore, the feature that explicitly allows users to identify content that should be protected—by selecting and applying a classification that then drives protection—is Sensitivity labels.