When someone uses the [OutputCache](http://msdn.microsoft.com/en-us/library/hdxfb6cy%28v=VS.71%29.aspx) directive in an ASP.NET WebForms/MVC application, does it actually do any caching server-side, like using the [Cache](http://msdn.microsoft.com/en-us/library/system.web.caching.cache.aspx) or does it only setup some properties in the Response object like the [Cache-Control](http://msdn.microsoft.com/en-us/library/cc251185%28PROT.10%29.aspx) property?

Cheers :)