The Elf has evolved into a category of beings, as opposed to a specific creature. As with the word human, to get the picture of an individual elf requires more information. Just as there are all kinds of humans or people (it takes all kinds?), there exists many types of elves and elven mixes. Yesterday, I spoke of the drow, or dark elves, just one sub race.
While the original concept of elves was Norse (álfar) or German, modern fantasy literature depicts elves as an almost divine race of beings with human stature and appearance, friendly natures (minus those from the dark side) and pointed ears (a must to my mind). The elves of today are different from traditional elves found in Middle Ages folklore and Victorian era literature.
The long and pointed ears seem to have started with Tolkien noting that the ears of elves were leaf-shaped. The length and shape of their ears depends on the artist, medium, or round-ear in question. I prefer pointed ears, but not the long ones like a donkey might have.

Modern fantasy elves (evolved from D&D or other role-playing media) may be immortal or slow maturing and long living compared to their humanoid cousins. They are also more attractive, smarter, gifted with magical power, and have a sharper sense of reality. Pure-blood elves do not possess facial or body hair. They are seldom portrayed as fat, lazy, or old.
Today, thanks to Tolkien, there are elf languages that have evolved and are often taken seriously and spoken by dedicated role players. Click here to get more information on the Elvish language.
The many types of elves include wood elves, high elves, aquatic elves, light elves, dark elves, sun elves, moon elves, forest elves, and savage elves. Even if you’re not an elf aficionado, you still should get the picture. If you are, you can add to the list.

Elves are more ancient than humans or other races and flourished in a sort of Golden Age forgotten by other races. The mixing of elves with other races is interesting in that it is a mix of the real world, with all its limitations, and fantasy worlds with its unlimited imagination.
If you discard the elf on the shelf and the comedy movie, Elf, staring Will Farrow, the best known modern elf is probably the archer Legolas Greenleaf, portrayed by Orlando Bloom in The Lord of the Rings film trilogy. Arguably Tolkien’s best-known elf. Good clips from the movie with great sound.
Cautiously, look both ways in fantasy and reality.
Mind the gaps if you mix the two.