title: What is the use of static variable in C#? When to use it? Why can't I declare the static variable inside method?
body: <p>I have searched about static variables in C#, but I am still not getting what its use is. Also, if I try to declare the variable inside the method it will not give me the permission to do this. Why?</p>
  
  <p>I have seen some examples about the static variables. I've seen that we don't need to create an instance of the class to access the variable, but that is not enough to understand what its use is and when to use it.</p>
  
  <p><strong>Second thing</strong></p>
  
  <pre><code>class Book
  {
      public static int myInt = 0;
  }
  
  public class Exercise
  {
      static void Main()
      {
          Book book = new Book();
  
          Console.WriteLine(book.myInt); // Shows error. Why does it show me error?
                                         // Can't I access the static variable 
                                         // by making the instance of a class?
  
          Console.ReadKey();
      }
  }
  </code></pre>