Out and Ref keyword in C#

This is difference between ref and out parameter:

• When we pass a ref parameter we must assign it a value.
• When we pass a out parameter do not need of assign a value.
• Out parameter in method we must assign a value before returning

static void Main(string[] args)
{

    string name = "Ahsan";
    SetName(ref name);
    Console.WriteLine(name);

    string occupation = "Engineer";
    SetOccupation(ref name, out occupation);
    Console.WriteLine(occupation);

    Console.ReadLine();
}
static void SetName(ref string name)
{
    if (name == "Ahsan")
    {
        Console.WriteLine("This is {0}",name);
    }
    name = "Wasim";//assign a new name
}

static void SetOccupation(ref string name, out string occupation)
{
    if (name == "Wasim")
    {
        occupation = "Student";
    }
    else
    {
        occupation = "Engineer";
    }
}

Out Put:

This is Ahsan
Wasim
Student