namespaces.cs

using System;
using Parent;

namespace Parent
{
    // another class in another namespace
    public class Child
    {
        public string getName()
        {
            return "Prateek";
        }
    }
}

namespace app
{
    public class Program
    {
        public static void Main(string[] args)
        {
            // using the class 'Child' of 'Parent' Namespace
            Child c = new Child();
            Console.WriteLine("Hello World! from "+c.getName());
        }
    }
}