The Verge tries to explain the different versions of Office 2013
Microsoft is offering a number of different Office 2013 editions aimed at home users and businesses. Office 365, the company’s software plus services platform for Office, will power Office 2013 as a subscription service for those who want to avoid the up-front costs of a perpetual license and take advantage of some of the on-demand features. Available in Home Premium, Small Business Premium, Pro Plus, and Enterprise — Office 365 has a variety of offerings that are flexible based on needs, but like many of its other products there’s still no one size that fits all. The new Home Premium product allows a family to install Office 2013 on up to five PCs and get an additional 20GB of online SkyDrive storage to share documents online. Home Premium includes access to Word, PowerPoint, Excel, Outlook, OneNote, Access, and Publisher through an Internet-connected Windows 7 or Windows 8 PC. Documents and settings, and even the actual apps will roam across whatever PC you choose to use Office 365 with. Other editions, like ProPlus and above, include additional user accounts and access to apps like InfoPath and Lync — designed for businesses. Office 365 will also include access to Office for Mac.