Namespace in C#.Net

Namespace

Namespace is logical division of class, structure and interface OR way to organize your Visual Basic .NET code is through the use of namespaces.
Namespaces are a way of grouping type names and reducing the chance of name collisions.
The namespace with all the built-in functionality comes under System namespace. All other namespaces comes under this System namespace.
Declaration of Namespaces:
// Namespace Declaration in C#
using System;
using System.Data;
// Namespace Declaration in VB
imports system;
imports system.Data;
Code Example :

namespace ExampleNamespace
{
class TestExample
{
public void ShowMessage()
{
Console.WriteLine("This is the TestExample namespace!");
}
}
}
Advantages:
We can establish security, version, reference, and deployment boundaries by using namespaces
Because of grouping of namespaces we can create hierarchy which is easy to identify classes by fully qualified names.