"How are the Father and the Son different?"
Hypostaticly.
"Trinity is simple unity; it is not merged together - it is three in one. The One three-hypostatical God has the three hypostases perfectly distinct in Himself." +Gregory of Sinai
Therefore, the Son is not, never has been, and never will be, the Father.
Any belief to the contrary is some form of monarchianism, whether Sabellian or modalist. This should also answer 7741.
I do deny that the Son is the Father. I do not retreat from that.
However, I will shortly retreat from this discussion. It's Saturday, and my calendar calls.