Namespaces are used to organize pre-coded classes, interfaces, and other types into logical and easy-to-reference units in the .NET framework class library. Instead of having many different and small library units, developers can include a whole group of library items to implement a certain functionality group. For instance, all library items about system input and output are grouped under one namespace.
The grouping of related FCL classes and other items into one namespace has many advantages. It makes it easier to locate specific library resources needed in an application. It also helps developers avoid naming conflicts in their code and also helps them organize application functionality.