Most humans don't actually know anything about the various monsters and magical creatures we sometimes encounter. We often only have so called 'adventurers' to go off, and only in recent years have scholars of major human nations had a chance to look into how these creatures exist.
For example, it's a myth that Fae live in a different plane of reality. Fae as we know them are individual sapient minds within a massive fungal network that spans multiple continents. If you see a Fae's body in our world that's merely a puppet made out of dead animal and plant parts used to interact with humans. And if you 'went to the Fae realm' what happened is that the fungal network fully incorporated your body and your brain generated visuals to comprehend the various intelligences interacting with you. Its also why you can't save someone whose been trapped in the Fae world for too long (there's no body left).
Another good example of how little most people understand non-human intelligences is people not understanding why they've only seen male dwarves. Dwarves are eusocial like ants or bees, their mountain homes are literally their hives. Those little bearded guys are the males, but the females look a lot different. Dwarf queens never leave the mountain they were born in, and every male dwarf in the colony thinks of her as being his beloved wife. Sterile female dwarves are a lot larger and less social than males, and are usually called 'trolls' by humans.
Unlike wizards, witches, or warlocks, sorcerers aren't just people with magic, they're there own type of creature. Don't trust them.
Elves all used to be human. They were an ancient magically advanced society who made a deal with a trickster god for eternal youth. The spell made them sexless along with being ageless, taking away their ability to ever reproduce to add new members of their society. This means that the number of elves will only every decrease, though their long lifespans and powerful magic means that this is a very slow process. This is also why elves are so androgynous, their bodies are sexless, they just still identify with genders because they used to be human. If you meet an elf probably don't ask them about any of this, it's something they're sensitive about.
Since gods were brought up it should be noted that there's no taxonomic definition of god. There's several different types of powerful beings that answer mortals' prayers that people call gods, but a lot of the different types of god have no relation to each other.
On the subject of powerful beings; most dragons people see are adolescent. A thousand-year-old dragon is about as advanced as a teenage human. Adult dragons are a cosmic species who lay their eggs on various planets and spend most of their time flying through space. Our world is just one of many planets they choose to nest on, and all the dragons we see are just ones who aren't big enough to get to space yet. Dragons grow throughout their lifetime, so some of the oldest dragons out in space are larger than continents.
Another species we only see a few of are sky people, who are a diverse and complex society, but since they live in settlements far above the clouds we rarely see them. The two groups we tend to see are powerful (usually male) magic users, who many have taken to calling angels. And lower class (usually female) raiders and gang members who go to the surface to hide from authorities, who many have taken to calling harpies. Neither of these groups are illustrative examples of what the sky people are like as a whole, but they're the only two social groups to regularly come to the surface.
On the opposite end of the spectrum of human assumptions, merfolk aren't an actual society, they're just fish that ate the souls of the drowned, and now they're stuck swimming around down there.
Another creature derived from humans are goblins, who are merchants and thieves whose greed led them to making a specific deal or stealing a specific type of cursed artifact, leaving them in a diminished, cannibalistic form. If a goblin eats enough sapient flesh, it will grow into an orc, and if an orc eats enough, it will become an ogre, and if an ogre eats enough, it will become a giant. If a goblin is able to overcome its greed it can become a human again, and the reason why there are some giants who are humanoid and peaceful is because they turned back into humans after they already grew past human size.
And now you know these things.
