A dwarf (Old Norse dvergr, Old English dweorg, Old High German twerg, Proto-Germanic *dwergaz) is a certain kind of invisible being in the pre-Christian mythology and religion of the Norse and other Germanic peoples. No one really knows what the word “dwarf” and its cognates originally meant, but there’s no indication that it had anything to do with a small stature, a characteristic which is never mentioned in ancient descriptions of these beings.
The dwarves are pitch-black in appearance and live underground in Svartalfheim, a place which was probably thought of as a labyrinthine complex of mines and forges.
The dwarves are most often noted for being extremely skilled smiths and craftspeople. Among the many irreplaceable treasures created by them are: Mjöllnir, the hammer of Thor; Gleipnir, the chain that bound the wolf Fenrir when all other fetters failed; Skíðblaðnir, a ship which belongs to Freyr and always has a favorable wind; Gungnir, the spear of Odin; Draupnir, a ring owned by Odin; the Brísingamen, a magnificent necklace owned by Freya; and the long, golden hair of Sif, Thor’s wife. They’re also extremely knowledgeable, wise, and magically powerful. They turn to stone if exposed to the rays of the sun.
Four dwarves, Austri, Vestri, Norðri, and Suðri (“East,” “West,” “North,” and “South”) hold aloft the four corners of the sky, evidencing their colossal strength.
The lines between the dwarves, elves, and dead humans are very blurry. The dwarves are occasionally called “black elves” (Old Norse svartálfar), and in some instances they’re described as being dead or resembling human corpses.
 Orel, Vladimir. 2003. A Handbook of Germanic Etymology. p. 81.
 Snorri Sturluson. The Prose Edda. Gylfaginning 17 & 34.
 The Poetic Edda. Völuspá, stanza 48.
 Turville-Petre, E.O.G. 1964. Myth and Religion of the North: The Religion of Ancient Scandinavia. p. 234.
 The Poetic Edda. Alvíssmál.
 Snorri Sturluson. The Prose Edda.
 Turville-Petre, E.O.G. 1964. Myth and Religion of the North: The Religion of Ancient Scandinavia. p. 235.