Microsoft 365 vs Office 365: What Changed

Microsoft 365 is a subscription-based suite of cloud services that bundles productivity tools (Office apps), cloud storage (OneDrive), communication (Exchange Online, Teams), device management (Microsoft Intune), identity and access management (Azure Active Directory), and security features (Microsoft Defender, Microsoft Purview). It was launched in 2017 as an evolution of Office 365, adding Windows 10/11 Enterprise licenses and Enterprise Mobility + Security (EMS) capabilities.

Office 365, originally launched in 2011, was a cloud-based version of the traditional Office suite, including Exchange Online, SharePoint Online, and Skype for Business (later replaced by Teams). It did not include Windows licenses or advanced security/device management features. In April 2020, Microsoft rebranded Office 365 as "Microsoft 365" for consumer and business plans, but the Office 365 name still exists for some enterprise plans (e.g., Office 365 E3) that are part of the Microsoft 365 family.

Microsoft 365 plans are divided into three main categories:

Office 365 plans (still available) include: - Office 365 Enterprise: E1, E3, E5 (without Windows or EMS). - Office 365 Business: Business Essentials, Business Premium (now part of Microsoft 365 Business). - Office 365 Education: A1 (free), A3, A5.

Key difference: Office 365 plans do NOT include Windows 10/11 Enterprise licenses or the full EMS suite (Azure AD P2, Intune, Advanced Threat Analytics). Microsoft 365 plans include these.

In 2020, Microsoft renamed Office 365 to Microsoft 365 for many plans to reflect that the suite is more than just Office apps. The change included:

However, the enterprise plans (E3, E5) kept the Office 365 name for the plans without Windows/EMS, while new Microsoft 365 E3/E5 plans were introduced. This dual naming persists.

In the Microsoft 365 admin center, you can see which licenses are assigned to users. To verify a user's licenses, navigate to Users > Active Users > select a user > Licenses and Apps. The license type will show either "Office 365" or "Microsoft 365" followed by the plan name. PowerShell can also be used:

Get-MsolUser -UserPrincipalName user@domain.com | Select-Object Licenses

This returns the SKU part number (e.g., "O365_BUSINESS_PREMIUM" for Office 365 Business Premium, which is now Microsoft 365 Business Standard).

Microsoft 365 relies on Azure AD for identity, Intune for device management, and Windows 10/11 for the client OS. Office 365 can be used with any device OS (Windows, macOS, iOS, Android) without requiring Intune or Azure AD P1. The exam tests that Microsoft 365 is a superset of Office 365, and that choosing between them depends on whether the organization needs device management and advanced security.

MS-900 objective 1.1: Describe the difference between Microsoft 365 and Office 365. Questions often present a scenario (e.g., "A company needs to manage employee devices and enforce conditional access policies. Which subscription should they choose?") and expect you to select Microsoft 365 over Office 365 because of Intune and Azure AD P1. Other questions ask which plans include Windows licenses (only Microsoft 365 plans).

Scenario 1: Small Business with Mobile Workforce A 50-employee marketing agency uses MacBooks and iPhones. They need Office apps, email, and file sharing. They do not need Windows licenses or device management because they use Apple devices. The appropriate choice is Microsoft 365 Business Standard (formerly Office 365 Business Premium) — it provides Office apps, Exchange Online, SharePoint, and Teams without requiring Windows. Misconfiguration: choosing Microsoft 365 Business Premium would add Intune and Azure AD P1, increasing cost unnecessarily. The agency would pay for features they can't use (Windows licenses don't apply to Macs).

Scenario 2: Large Enterprise with Compliance Requirements A financial services company with 10,000 employees needs to enforce data loss prevention (DLP), retain emails for 7 years, and manage devices with conditional access. They also need Windows 10 Enterprise for security features like BitLocker and Credential Guard. The correct plan is Microsoft 365 E5, which includes Office 365 E5, Windows 10/11 Enterprise E5, and EMS E5. Common mistake: choosing Office 365 E5 plus Windows 10 Enterprise E5 plus EMS E5 separately — this costs more and is harder to manage. The exam tests that Microsoft 365 E5 bundles everything.

Scenario 3: Educational Institution A university wants to provide free Office apps to students and staff. They choose Office 365 Education A1 (free) for students and Microsoft 365 Education A3 for faculty (includes Intune for device management). The exam tests that A1 is free but does not include desktop Office apps (only web and mobile). For desktop apps, they need A3 or A5.

What Goes Wrong When Misconfigured - Assigning Office 365 E3 to users who need Intune: users cannot enroll devices in MDM. - Assigning Microsoft 365 E5 to users who only need email: waste of money. - Not understanding that Microsoft 365 Business plans are limited to 300 users: a growing company may hit the cap and need to migrate to Enterprise plans.