SharePoint 2013 has a number of changes since SharePoint 2010. This is a list of some of the features and discontinued functionality. If you want a quick look at what has been discontinued or modified – read further.
Some of the features that have been discontinued may continue to operate in SharePoint 2013
Some of notes:
When you create a site, all Meeting Workspace site templates (Basic Meeting Workspace, Blank Meeting Workspace, Decision Meeting Workspace, Social Meeting Workspace, and Multipage Meeting Workspace) are not available. I know some environments that heavily use workspaces and I’m keen to inform them about this change.
for SharePoint has now been integrated into SharePoint 2013. So a lot of features have changed in this space. One of them is the Search RSS feeds being discontinued and another is the Web Analytics are part of the Search service.
Office Web Apps server has sort of divorced from SharePoint 2013. 2 years ago with SharePoint 2010 they were inseparable! So a lot of functionality has changed in this space. In case you didn’t know, you cant install Office Web Apps on the same server as SharePoint 2013, it doesn’t allow you to. It has to reside on a separate server.
for more info:Discontinued features and modified functionality in Microsoft SharePoint 2013