In Microsoft Systems Management Server (SMS), an alias for a set of sites. You use site groups to limit jobs to a specific set of sites.
For example, if you want to distribute software to servers at all your sales sites, you can create a site group that contains all sales sites in your company and then use this group to limit the scope of the job to servers at only those sites.
You can also use site groups to limit the scope of a query or an alert.