When we pass a parameter as ref to a method, the method 
refers to the same variable and changes made will affect 
the actual variable. even the variable passed as out 
parameter is same as ref parameter, but implementation in 
c# is different, 
Arguement passed as ref parameter must be initialized 
before it is passed to the method. But in case of out 
parameter it is not necessary. But after a call to a method 
as out parameter it is necessary to initialize.
When to use out and ref parameter, out parameter is used 
when we want to return more than one value from a method.