There are 2 types of report server modes and given in below screen with available options in SQL 2012. The 2 modes are Native & SharePoint. With native mode you get all the features available to operate your reporting services. But with SharePoint mode you get to manage the SSRS environment using your local SharePoint. By operating via sharepoint mode, you can enable all your intranet users to get to access to SSRS environment within the same application but it does have its own downside like it does not support linked reports, my reports, my subscriptions.