What is Microsoft 365?
An overview of Microsoft's cloud productivity suite — what's in it, who it's for, and how the pieces fit together.
Microsoft 365 is Microsoft's subscription bundle of cloud-based productivity software. It combines the familiar desktop apps — Word, Excel, PowerPoint, and Outlook — with online services for collaboration, communication, identity, and security. Where the older "Office" brand referred to a one-time-purchase set of desktop tools, Microsoft 365 is delivered as an ongoing service that updates continuously.
What you actually get
A typical business subscription includes:
- Office apps: Word, Excel, PowerPoint, Outlook, and OneNote — both as installable desktop apps and in the browser.
- Email and calendaring: Exchange Online, with mailboxes hosted by Microsoft.
- File storage: OneDrive for personal files and SharePoint for shared team libraries.
- Communication: Microsoft Teams for chat, meetings, and calls.
- Identity and access: Microsoft Entra ID (formerly Azure AD) for sign-in, groups, and permissions.
- Security and management: Microsoft Defender, Purview, and Intune for protecting data and managing devices.
- Automation and analytics: Power Automate, Power BI, and Power Apps on the higher tiers.
How the pieces connect
The point of buying these tools together — instead of stitching them together yourself — is that files, identities, and permissions flow between the apps without you wiring anything up. A document drafted in Word can be co-edited in a Teams channel, stored in a SharePoint library, secured by Entra ID Conditional Access, and discoverable in Microsoft Search, all out of the box.
Microsoft 365 vs Office 365
The "Microsoft 365" brand replaced "Office 365" in 2020. The core productivity services are the same, but Microsoft 365 plans also bundle Windows licensing and device-management features on the higher business and enterprise tiers. You'll still see the Office 365 name in some plan SKUs and on legacy admin screens.
Who it's for
Microsoft 365 is sold in Business plans (up to 300 users), Enterprise plans (no cap, with deeper security and compliance tooling), Frontline plans for deskless workers, Education plans, and consumer Family and Personal tiers. If you're new to the platform, the rest of this site explains each piece in plain English.