SERVERPROPERTY Function

SERVERPROPERTY Function returns property information about the server instance.

Level of the version of the instance of SQL Server.
SELECT SERVERPROPERTY('ProductLevel')

Returns one of the following:
'RTM' = Original release version
'SPn' = Service pack version
'Bn', = Beta version


Installed product edition of the instance of SQL Server
SELECT SERVERPROPERTY('Edition')

Name of the instance the user is connected
SELECT SERVERPROPERTY('InstanceName')

Server instance is configured in a failover cluster
SELECT SERVERPROPERTY('IsClustered')

Consult BOL for other SERVERPROPERTY propertyname