Naming a piece of code

A method is a named block you can call as often as you like. You have been using one all along: Main.

using System;

class Program
{
    static void Greet()
    {
        Console.WriteLine("Hello!");
    }

    static void Main()
    {
        Greet();
        Greet();
    }
}

Hello!
Hello!

void means it returns nothing — it just does something. Empty parentheses mean it needs nothing from you.