Function module

Hi all,

1) what is diff b/w pass by value and pass by reference?

2) in normal function module it is accepting the parameters as by value and by ref

but in RFC F.M it is not accepting the by reference what is reason behind this ?

3 ) when we go for Return Tab and when we go for exception tab ?

4) if it is normal f.m then we can go for exception am i correct? and if it is RFC F.M then we go for return(pass by val) is it right?

Thanks in advance

Rambabu.A