What is a local variable and where can it be declared in C#?

public class Program 
{
  public static void Main() 
  {
		var myFirstVariable = 1;
		
		// The variable myFirstVariable will be accessible here
		if (myFirstVariable >= 1) 
       {
		  var mySecondVariable = 15;

		  // The variable myFirstVariable will be accessible here,
		  // because it was declare in parent block statement and
		  // the current block statement is nested in this statement.
		  
		  // The variable mySecondVariable will be accessible here.
		  
		}
		
		// The variable myFirstVariable will be accessible here
 
        // The variable mySecondVariable won't be accessible here,
		// because it was declared in a different block statement
		// and we are already outside of it.

  }
}