SHAREPOINT 2013 APP MODEL
You can install SharePoint in two primary ways. As with SharePoint 2010, you can install the full version of SharePoint Server and have all of your assets and content running in an on-premises environment. Alternatively, you can provision an instance of Office 365 (O365) and then take advantage of SharePoint Online (or a cloud-hosted version of SharePoint). You saw some examples of SharePoint Online in Chapter 1, “Introduction to SharePoint 2013,” and you’ll see more in this chapter. Irrespective of how you deploy your SharePoint instance, the new app model for SharePoint holds true for both on-premises versions of SharePoint (SharePoint Server) and cloud-hosted versions (O365).
Although you have the ability to manually create SharePoint 2013 site collections and configure and brand those sites to your business needs, this book is about development. One of the key evolutionary areas in SharePoint 2013 is the new app model. You implement the new cloud model, broadly speaking, through the creation and deployment of either Apps for SharePoint or Apps for Office.
Apps for Office