Office 365 vs Microsoft 365

The names get used interchangeably, but they are not the same. Microsoft 365 is Office 365 plus more: Windows and the security layer. Here is the clean version.

The clean definition

Think of it as one inside the other. Office 365 gives you the productivity apps and the cloud services behind them: Word, Excel, PowerPoint, Outlook, plus Exchange email, SharePoint, and Teams.

Microsoft 365 includes everything in Office 365 and then adds two things: Windows Enterprise and the Enterprise Mobility and Security layer (Intune for device management, Entra for identity). So Microsoft 365 is the productivity suite plus the tools to secure and manage the devices and people using it.

Side by side

Plan names vary by segment. Enterprise still has Office 365 E3 and E5 alongside Microsoft 365 E3 and E5. For small business, the old Office 365 Business plans became Microsoft 365 Business in 2020. Confirm current SKUs with your Microsoft partner.

A common source of confusion

At the enterprise level, both families still exist: Office 365 E3 and E5 sit next to Microsoft 365 E3 and E5. The Microsoft 365 versions add Windows Enterprise and the security layer on top of the Office 365 versions. For small business, there is no more Office 365 Business, so the choice is simply which Microsoft 365 Business plan.

Which one you need

Choose Office 365 if you only need the apps and email and you handle device management and security another way. Choose Microsoft 365 if you want one integrated stack that also secures and manages your devices and identities, which is what most businesses want today.