1.2.1. The Admin Center Ecosystem
š” First Principle: Microsoft 365 is governed through a family of purpose-built admin centers ā each one owns a specific service's configuration surface. The Microsoft 365 admin center is the hub; workload-specific centers (Exchange, SharePoint, Teams, Purview, Entra) handle the details.
Think of it like a hospital. The hospital administration manages org-wide policies (hiring, billing, facility access). But clinical decisions for cardiology happen in the cardiology department, not at the front desk. Similarly, you configure tenant-wide settings (domain names, org policies) in the M365 admin center, but you configure mailboxes in Exchange Online, sites in SharePoint, and threat protection in Defender.
| Admin Center | Primary Objects | What You Configure There |
|---|---|---|
| Microsoft 365 admin center | Users, groups, licenses, domains | Org settings, user creation, license assignment, domain verification |
| Exchange Online | Mailboxes, distribution lists, shared mailboxes | Mail flow rules, mailbox settings, retention policies for email |
| SharePoint | Sites, libraries, folders | Site creation, sharing settings, storage limits, hub sites |
| Teams | Teams, channels, policies | Meeting policies, messaging policies, voice, guest access |
| Microsoft Entra | Users, groups, apps, roles | Conditional Access, MFA, SSO, PIM, app registrations |
| Microsoft Purview | Labels, policies, cases | DLP, sensitivity labels, retention, Insider Risk, eDiscovery |
| Microsoft Defender | Alerts, incidents, policies | Anti-phishing, safe links, safe attachments, endpoint protection |
ā ļø Exam Trap: Email security policies ā anti-phishing, safe links, safe attachments ā live in the Microsoft Defender portal, not the Exchange admin center. The Exchange admin center manages mailbox objects and mail flow. This is one of the most commonly tested distinctions on AB-900.
Reflection Question: An admin needs to configure a policy that blocks users from forwarding emails containing credit card numbers. Which admin center do they use, and why?
