A: Collections can be created with static and dynamic rules. Using dynamic rules, certain attributes of the machines in the Configuration Manager database can be queried.
If matches are found, the machines are placed into the collection. Two attributes of the OS information for a machine that can be useful are Version and Name. When combined, they can uniquely identify Windows 2012 servers.
For each version of Windows, there is a unique version number:
|Windows Server 2012/Windows 8||6.2|
|Windows Server 2008 R2/Windows 7||6.1|
|Windows Server 2008/Windows Vista||6.0|
|Windows 2003/Windows XP 64-bit||5.2|
Notice that the client and server share the same version number for Windows 2008 and later, so the version number needs to be combined with something else to uniquely identify server vs. client. One option is to use the name of the OS.
In the rule below, I use an OS version of 6.2 combined with the OS name, which must contain the word server.
System Center 2021 Configuration Manager Collection Criteria Tab