Hosting Options for the SharePoint 2013 App Model
    SharePoint Hosted:  A SharePoint-hosted app is one that contains no server-side components. Everything that it needs to function, such as lists, libraries, etc., it is able to deploy within the SharePoint environment.  Provider Hosted:  A Provider-hosted app is one that has server-side components. These components are usually contained within an ASP.NET application and you have to provide a separate environment to host them. These server-side pieces can be developed in any technology as long as you can leverage OAuth and make REST calls.  Auto-Hosted:  An Auto-hosted app runs on Office 365 and its SharePoint Online offering. Like a provider-hosted application, an auto-hosted app has server-side components, but when you deploy the app to SharePoint, the service fires up the server-side elements in an Azure layer.     App Scope   An app for SharePoint has an app scope. The two possible app scopes are  web scope  or  tenant scope . The difference is n...