Everything. They have absolutely nothing in common.
Beer nuts are over a dollar deer nuts are under a buck. (old but good)
E.T learned English and wanted to go home.
Works it out with a pencil.
He works it out with a pencil.
A Specialist knows more and more about less and less until he knows absolutely everything about nothing. A Generalist knows less and less about more and more until he knows absolutely nothing about everything.
Absolutely nothing.
One shoots but can't hit, the other hoots but can't sh...