| Gather 'round the campfire|
A dwarf is a mythological creature. Dwarves are humanoid, but shorter and uglier. They are frequently depicted with extremely large and bushy beards. In some stories, either dwarves have no women at all, or dwarf-women just happen to look exactly like the men (complete with beards), with all of their feminine features hidden under twelve layers of armour. Dwarves are usually depicted as very skilled craftsmen, known for their cunning inventions and fine metalwork. They are also miners, constantly looking for precious materials. Dwarves sometimes use magic, but usually don't cast flashy magical spells; instead, they create magical weapons, armour, and charms.
Mythology and fantasy literature
In Norse mythology, four dwarves hold up the four corners of the sky. Dwarves overlap somewhat with the "black elves" that in the Prose Edda are listed as the inhabitants one of the Nine Worlds, Svartalfheim.
Dwarves are also a staple in modern fantasy literature, due in large part to the influence of J.R.R. Tolkien, who began his literary depictions of dwarves by directly ripping off Norse mythology — going so far as to take almost all of the dwarf names in The Hobbit straight out of a long list in the Eddaic poem Voluspa. In modern fantasy media, they are almost always portrayed as Scottish, Nordic or Russian.
In real life, dwarfism is a catch-all for a number of health conditions resulting in extremely short stature. Historically, people with some of these health conditions were called "dwarfs" (distinct from the dwarves of modern fantasy), but nowadays the polite term is "little people." And no, contrary to claims made by young earth creationist Jim Pinkoski, the existence of very short people nowadays does not prove that Adam was 15 feet tall.