Namespaces are program elements designed to help us organize our programs. They also provide assistance in avoiding name clashes between two sets of code. Implementing Namespaces in our own code is a good habit because it is likely to save us from problems later when we want to reuse some of our code. For example, if we create a class named Console, we would need to put it in our own namespace to ensure that there wasn't any confusion about when the System.Console class should be used or when our class should be used.

Example

// Namespace Declaration
using System;

namespace newnamespace
{
    // Program start class
    class space
    {
        public static void Main()
        {
            // Write to console
            Console.WriteLine("This is the new Namespace."); 
        }
    }
}

In the example above we have declared the new namespace by putting the word namespace in front of newnamespace.  Curly braces surround the members inside the newnamespace namespace.

Nested Namespace

// Namespace Declaration
using System;

namespace newnamespace
{
    namespace first
    {       
        class space
        {           
            public static void Main()
            {
                // Write to console
                Console.WriteLine("This is the new first Namespace.");
            }
        }
    }
}

Namespaces allow us to create a system to organize our code. A good way to organize our namespaces is via a hierarchical system. We put the more general names at the top of the hierarchy and get more specific as we go down. This hierarchical system can be represented by nested namespaces. The code above shows how to create a nested namespace.