Alignment question

Question

Console.WriteLine( "{0,-6}", -123);

 

This output is giving result -123 and the cursor is not moved by 3 digits.

 

Whereas

 

Console.WriteLine( "{0,6}", -123); 

 

this is gving output -123 after the cursor is moved by 3 digits. 

 

Basically i dont understand in which case "{0,-6}" willl be useful?