Microsoft Office 365 is different from the old Microsoft Office, which dates back to 90s, in two major aspects. First Instead of having a perpetual license, office 365 is licensed as a monthly or yearly subscription model. Second, It mainly focuses on online storage and cloud services, along with business class emails and traditional Microsoft desktop apps. Office 365 come up with a number of editions where each plan is different in accordance with its pricing. Different packages will have different features. The number of apps and services available in an Office 365 subscription depends on the edition you have chosen.