SQL Server Management Objects (SMO) has various namespaces. The different namespaces represent different areas of functionality within SMO.
In SQL Server 2008, the SMO assemblies are located in the C:\Program Files\Microsoft SQL Server\100\SDK\Assemblies\ folder.
The SMO namespaces are:
Contains instance classes, utility classes, and enumerations that are used to programmatically manipulate Microsoft SQL Server.
Contains the classes that are common to Replication Management Objects (RMO) and SMO, such as connection classes.
Contains classes that represent the SQL Server Agent.
Contains classes that represent the WMI Provider.
Contains classes that represent Registered Server.
Contains classes that represent Database Mail.
Contains classes that represent the Service Broker.