With Office 365 subscription plans you get the full, installed Office applications: Word, Excel, PowerPoint, OneNote, Outlook, Publisher, and Access. (Publisher and Access are available on PC only.) You can install Office 365 across multiple devices, including PCs, Macs, Android tablets, Android phones, iPad, and iPhone. In addition, with Office 365 you get services like online storage with OneDrive and Skype minutes for home use. When you have an active Office 365 subscription, you always have the most up-to-date version of the Office applications.
Office as a one-time purchase includes applications such as Word, Excel, and PowerPoint for use on a single PC or Mac. The applications are not automatically updated; to get the latest version, you must purchase Office again when the new version becomes available. The latest versions currently available for one-time purchase are Office 2013 for Windows and Office 2011 for Mac. Previous versions include Office 2010, Office 2007, Office 2008 for Mac, and Office 2004 for Mac. Office 2010 and Office 2007 are compatible with Windows 8.1 and earlier. Office as a one-time purchase does not include any of the services included in Office 365.