SBS includes a customized and configured version of Windows Server Update Services (WSUS). The SBS team has already done the heavy lifting to get WSUS configured and working optimally for SBS networks. When the SBS install is finished, updates are already being managed and deployed, but you can do additional customization from the Updates page of the Windows SBS Console.
The default software update settings for SBS 2011 are adequate for most small businesses, but there are additional settings you can use to customize how updates are handled on your network. You can
Change the update level for servers and clients.
Change the update schedule.
Change which computers are managed by WSUS.