Simple Explanation of The Differences Between Office 365, Microsoft 365 and Windows 365

It is difficult to understand what Microsoft if offering these days.  It was hard enough when there was just Office 365 with the E1 E3 and E5 packages but today Microsoft is offering 3 different bundles (Office, Windows & Microsoft) each with their own E1 E3 and E5 sub-bundles.

What is Office 365?

In simple terms, Office365 is a bundle of software that (for most packages) provides Word, Excel, PowerPoint, Outlook and more on the desktop through a local install plus OneDrive cloud storage and a hosted Exchange mail server.

What is Windows 365?

In simple terms, Windows 365 is a Windows 10 for the desktop subscription.  Note that Windows 365 is not a real thing.  Microsoft has decided to call its Windows subscription model “Windows E1″ Windows E3” and Windows “E5”, but we find that very confusing so we promote it as Windows 365 which makes more sense to our customers.

What is Microsoft 365?

In simple terms, Microsoft 365 is Office 365 + Windows 365 which means you are buying a subscription to Microsoft Office (Word, Excel, PowerPoint…) and a subscription to Windows 10.

What are the different Bundles Microsoft Offers?

Below are the three (of many) Entry Level bundles (E1’s and F1’s) available as of October 2018:

Below are the three (of many) Mid-Level bundles (E3’s) available as of October 2018:

Below are the three (of many) High-Level bundles (E5’s) available as of October 2018:

Note that we provide a free 30 day trial of Office 365 to small and medium businesses HERE but if you are enterprise scale we recommend using a larger provider like PCM.


  1. Avatar
    Anne April 16, 2020 at 6:54 am

    Hi I agree with Shannon, I have purchased office 365 but I do not have Word 2016 which I have to have to take my Advanced Word course, why do I have only Word 2003?

    • Ian Matthews
      Ian Matthews April 16, 2020 at 7:50 pm

      Hi Anne;

      I think you are confusing BUILD numbers with VERSION numbers. As explained in this article MS no longer releases product named after the year (i.e. Office 2007 or Office 2016). Now, instead of releasing new features every 3 years, they are released twice per year. ALL Office subscriptions are now called Office 365 ProPlus. The version numbers are the coded YYMM meaning that most people have 2003 right now… that is MARCH 2020. The fall build of Office will be coded 2009 for Sept 2020 and the Spring 2021 release will most likley be coded 2103.

      To confirm your build number is happy and current see MS’ list of builds here:

  2. Avatar
    Gianni Bissi April 8, 2020 at 12:38 am

    Very Clear Explanation
    Thank You : )
    Gianni, from Italy

  3. Avatar
    Shannon Rooney February 1, 2020 at 7:13 pm

    I believe your definition of “simple” and mine is very different. This clarified nothing.

    • Ian Matthews
      Ian Matthews February 10, 2020 at 8:32 pm

      Hi Shannon;

      What is it that is not clear?

      Office365= MS Office Suite + OneDrive and Email
      Windows365= Windows 10 license subscription
      Microsoft365 = Office365+Windows365

      Is that helpful?

Questions or Comments?