Welcome to Microsoft 365
Microsoft 365 is more than Office apps. It's an entire ecosystem of productivity, collaboration, security, and compliance tools — all connected by a single identity. Let's explore what's inside.
What is Microsoft 365?
Think of Microsoft 365 as a shopping centre, not a single shop.
Each shop (app) does something specific — Outlook handles email, Teams handles meetings, SharePoint stores documents. But they’re all in the same centre, sharing the same security cameras (Entra ID), the same management office (admin center), and the same rules (compliance policies).
The power isn’t in any single app — it’s in how they’re all connected. Your identity follows you everywhere. Your files are accessible from any app. And your admin controls everything from one dashboard.
The M365 ecosystem at a glance
| Category | Services | What They Do |
|---|---|---|
| Productivity | Word, Excel, PowerPoint, OneNote | Create and edit documents, spreadsheets, presentations |
| Communication | Outlook, Exchange Online | Email, calendar, contacts |
| Collaboration | Teams, SharePoint, OneDrive, Loop | Meetings, chat, file sharing, real-time co-authoring |
| Security | Microsoft Entra ID, Defender XDR | Identity, access control, threat protection |
| Compliance | Microsoft Purview | Data protection, DLP, retention, eDiscovery |
| AI | Microsoft 365 Copilot, Agents | AI-powered productivity and automation |
| Management | M365 admin center, specialised admin centers | Configuration, monitoring, licensing |
Key exam concept: Microsoft 365 isn’t just “Office in the cloud.” It includes security (Entra, Defender), compliance (Purview), and AI (Copilot) — all managed together. The exam tests your understanding of the FULL ecosystem.
The Microsoft 365 admin center
The admin center (admin.microsoft.com) is your command dashboard. From here, you can:
- Manage users and groups — create accounts, assign licenses, reset passwords
- Configure domain names — add and verify your organisation’s domains
- View organisation settings — company name, address, language preferences
- Monitor service health — check if M365 services are running normally
- Access billing — view subscriptions, invoices, and license counts
- Navigate to specialised admin centers — Exchange, SharePoint, Teams, Entra, Purview
The specialised admin centers
The M365 admin center links to specialised admin centers for deeper management:
| Admin Center | URL | What You Manage |
|---|---|---|
| Exchange | admin.exchange.microsoft.com | Mailboxes, distribution lists, mail flow |
| SharePoint | admin.sharepoint.com | Sites, libraries, sharing settings, storage |
| Teams | admin.teams.microsoft.com | Teams, channels, meeting policies, voice |
| Entra | entra.microsoft.com | Identity, CA policies, SSO, app registrations |
| Purview | purview.microsoft.com | DLP, sensitivity labels, retention, compliance |
| Defender | security.microsoft.com | Threat protection, incidents, security posture |
Exam tip: Know which admin center handles what. The exam loves “Where does Maya go to configure X?” questions. The M365 admin center is the starting point; you navigate to specialised centers for specific workloads.
Domain names and organisation settings
When Maya sets up Northwave’s M365 tenant, the first things she configures:
Domain names
- Default domain:
northwave.onmicrosoft.com(auto-generated) - Custom domain:
northwave.com(needs DNS verification) - Users sign in with
maya@northwave.cominstead ofmaya@northwave.onmicrosoft.com
Organisation settings
- Company name, address, phone number
- Language and time zone defaults
- Release preferences (Standard vs Targeted release)
- Organisation profile visible across M365 apps
Targeted release — what admins should know
Microsoft offers two release tracks:
- Standard release — new features roll out to everyone at the normal pace
- Targeted release — early access to new features for selected users or the whole org
Maya can set specific users (like herself) to Targeted release to preview changes before they hit the whole company. This is useful for testing Copilot updates, new admin features, or UI changes.
Where: M365 admin center → Settings → Org settings → Release preferences
Microsoft Graph — the invisible backbone
Every M365 service connects through Microsoft Graph. Think of it as the nervous system:
- Users → who you are
- Files → your documents in SharePoint and OneDrive
- Emails → your Outlook messages
- Calendar → your meetings and events
- Teams chats → your conversations
- Sites → your SharePoint sites
When Copilot answers “What’s the latest on Project Phoenix?”, it queries the Graph across ALL these data types. When an admin pulls a usage report, it comes through the Graph. When a compliance policy scans for sensitive data, it reads from the Graph.
Key exam concept: Microsoft Graph is what makes M365 an integrated ecosystem rather than a collection of separate apps. It’s the foundation that Copilot, admin reports, and compliance tools all rely on.
🎬 Video walkthrough
🎬 Video coming soon
Welcome to Microsoft 365 — AB-900 Module 1
Welcome to Microsoft 365 — AB-900 Module 1
~10 minFlashcards
Knowledge Check
Maya needs to verify Northwave's custom domain name (northwave.com) so employees can sign in with their company email. Where does she configure this?
Which component of Microsoft 365 connects all services together and enables features like Copilot to query across emails, files, and Teams chats?
Next up: Exchange Online — managing mailboxes and distribution lists in the Exchange admin center.