Default Groups

     In Windows Server 2012 server automatically creates several groups. These so-called Default local groups, they include Well-known groups such as administrators, Backup Operator and the Remote Desktop Users. But there are some in the creation of additional groups Domain, both built-in and user container, this includes domain administrators, enterprise administrators, and schema administrator. 

     The default groups that need to carefully manage Administrator privileges, because they usually have greater privileges than for most of the necessary trust environment, because they are often applied to protect their members. 

    You should try to avoid adding to the user group has no default members (Accounts Operators, Backup Operators, Server Operators, and Print Operators). Instead, create a custom group, Assign permissions and user rights to achieve your business and management needs.