Namespaces are the way to organize .NET Framework Class Library into a logical grouping according to their functionality, usability as well as category they should belong to, or we can say Namespaces are logical grouping of types for the purpose of identification.

The .NET Framework Class Library (FCL ) is a large collection of thousands of Classes. These Classes are organized in a hierarchical tree. The System Namespaces is the root for types in the .NET Framework. We can uniquely identify any Class in the .NET Framework Class Library (FCL ) by using the full Namespaces of the class .In .Net languages every program is created with a default Namespaces . Programmers can also create their own Namespaces in .Net languages.