Patching SharePoint is a two-step process. The updated binaries are first installed and then psconfig must be run to update the SharePoint databases. SBS 2008 uses Windows SharePoint Services 3.0 and updates automatically run PSconfig when installed via Automatic Updates or Windows Server Update Services. SharePoint Foundation 2010 changes the method in which patches are installed. PSconfig no longer runs automatically after an update is installed. The SharePoint binary files are updated with the patch but the databases are not automatically upgraded. SharePoint runs in a compatibility mode that still allows the sites to function with the older version databases.