Long time geek, fangirl, mother, and reader. I've got a lot to say, you might not like it all, but it will be honest and hopefully helpful.
Oh look the old fan fiction vs. fanfiction.
Please note: The people who make the distinction usually are old school hardliners who look down on what they call fanfiction (use of other's characters, worlds and plots), verses fan fiction using worlds, settings or writing what is essentially Real People fan fiction (RPF).
Prime example: George RR Martin wrote fan fiction, but forbids fanfiction of his own work.
It's different because, you know, reasons. Whatever.