There are more types of Elves in more mythologies than I care to list and define here. Suffice it to say, there's an elf for just about anything---- from wood elves, snow elves, moon elves, aquatic elves to Christmas elves.
And, whether they are like the androgynous beauties of Middle-Earth or the tiny Cobbler elves that are more synonymous with gnomes or dwarves, elves are all connected to some form of magic... or, magick.
Most elves resemble the physical form of humans. Even the most diminutive of elves, are distinctly human-looking--with one singular difference given to just about every 'species' of elf----pointy ears.
Am I saying that every humanoid creature with pointy ears is an elf? Certainly not.... otherwise Mr. Spock might have some explaining to do. Just that the story description of elves, especially the more modern elf-lore, depicts elves as having pointy ears.
The name 'elf' derives from the Old English aelf and is seen in ancient words such as, aelfadl (nightmare) and aelfsogooa (elf-sucking or hiccough).
Ancient superstitions held that mishaps and ailments were brought about by elves--- hence the origins of the phrase "affected by elves." Lucky for us that most conditions and disorders can now by traced/linked to decidedly non-elf origins. Though there are still a few afflictions out there which are probably still attributed to "elf-meddling" because of their bizarre nature.
The elves of early lore were mostly mischievous, even sinister and make their appearance in many ballads and folk tales. In fact, it isn't until the more recent tales, that elves have become synonymous with beauty and wisdom.
And, I, for one, am glad about the elves' evolution. I'd much rather come face-to-face with an ethereal beauty divining from the stars than a comical creature determined to give me the hiccoughs.
Nowhere on Earth you can't find us,
tasting air sweet and thick with midnight,
listen close to the raindrop's soft sigh,
this is just a smidgen of Elven delight.
Our home can be but a fig-leaf,
or a cavernous mountain abode.
You can catch sight of us chasing a rainbow,
or wand'ring some lost woodland road.
Some of us enjoy the tricksies,
others the histories of old,
every one of us cherishes the quiet.
There's long-winded stories to be told.
Don't think us all evil, black-minded,
though some like the jokes that they play,
the rest of us enjoy the night sky,
and the moon-morning kiss each new day.