ref keywords: When we want change in passed parameter to the method then
we pass it by reference with the help of ref keyword in actual and formal
parameters. By passing parameter by reference actual address of the parameter
is passed to the method and changes made to the parameter in method reflect in
actual parameter passed. out Keywords Passing parameter by out is somewhat like ref but the
difference is that it is unidirectional i.e. we do not need to initialize the
passed variable but we get back the processed value. Likewise Reference
parameter we need to use out before variable in output parameter.