You will find that
different is used much more often than
unlike.
unlike can be used as a preposition to show contrast. It's the opposite of
like.
Sara stays at home all day -- unlike Jane, who is usually out shopping!
I'm surprised that Henry is late. It's very unlike him to be late.
(You can't substitute
different in these sentences.)
__________
In other constructions
unlike can be used as the equivalent of
different from, but most people say
different from, not
unlike.
This picture is [ unlike / different from ] that one.
(Some people say
different than; some say
different to.)
_________
When there is no complement,
different is used almost exclusively.
These pictures do not resemble each other at all. They are completely different. (You can substitute
unlike, but it isn't the usual way to say it.)
CJ