Namespaces can be defined as organizing the classes. It provides a way to keep one set of name separate from other set of name. Classes defined in one namespaces cannot conflict with other namespaces having same class name. The biggest advantages of using namespaces that class having same name cannot clash or conflict with other class when they defined in different namespaces. It is also called as named group of classes having common features. Namespaces can also include structures, interfaces, and delegates. Within namespaces no two classes have the same name

To define namespaces in C# we use keyword namespace followed by namespace name and curly braces containing body of the namespace.

Syntax

Namespace name_of_namespace 

{

//classes

//delegates

//structures

//interfaces

} 

To access namespace we use dot (.) operator in C#.

Syntax

Namespace_name.class_name.method_name

using System;

namespace first_space { 
class namespace_cl {
 public void func() {
Console.WriteLine("Inside first_space");
}
}
} 
namespace second_space {

   class namespace_cl {

      public void func() {

         Console.WriteLine("Inside second_space");

      }

   }

}

class TestClass {

   static void Main(string[] args) {

      first_space.namespace_cl fc = new first_space.namespace_cl();

      second_space.namespace_cl sc = new second_space.namespace_cl();

      fc.func();

      sc.func();

      Console.ReadKey();

   }

}

When the above code is compiled and executed, it produces the following result −

Inside first_space

Inside second_space