What Purview includes
Purview is the umbrella for at least eight separate capabilities: Information Protection (sensitivity labels, encryption, rights management), Data Loss Prevention, Records Management, Retention, eDiscovery (Standard and Premium), Insider Risk Management, Communication Compliance, and Privacy Risk Management. Microsoft brought all of them under the Purview brand in 2022; before that they were 'Microsoft 365 Compliance' or sat individually in Office 365.
What's in E3 versus E5
E3 includes the Purview baseline: sensitivity labels (manual labelling, basic encryption), retention policies, basic DLP across SharePoint and Exchange, eDiscovery Standard. E5 (or E3 + the Microsoft 365 E5 Compliance add-on) adds the full suite: auto-labelling, advanced DLP across endpoints and Teams, Insider Risk Management, Communication Compliance, Records Management, Privacy Risk Management and eDiscovery Premium.
Why it matters for Australian tenants
Purview is how Microsoft 365 satisfies Australian Privacy Act 'reasonable steps', NDB scheme readiness, sensitive information classification, and the data-classification expectations under APRA CPS 234, SOCI and Essential Eight ML2. For Copilot rollouts it's also the prerequisite — auto-labelling, DLP-for-Copilot and container labels are Purview features.