The problem with the word "Elf" as it is used today is that most elves are not mythological Mythology/Elves of terrestrial origin. Many of them, such as the {{Elenari}}, come from other planets or entirely different planes of existence. Nevertheless, although the term "Elf" gets used to describe any number of different species, we can at least define some common characteristics:

• Physiology. Elves almost universally have pointy ears. In some cases, there is significant sexual dimorphism: male elves are tall and slender while female elves are shorter and more curvy. In other cases, both male and female elves are described as being tall and slim. Pigmentation varies from species to species; there are reports of pale skin, tan skin and pitch-black skin, and any number of colors for eyes and hair.
• Connection with nature. Most if not all elvish species are closely connected to the land on which they live. Forests are common dwelling places for elves (often with houses built in or on the trees themselves), but there are reports of elven tribes living on plains, in the mountains, underground and even underwater.
• Level of technology. Most elven tribes have a level of technology roughly equivalent to that of Mediaeval Europe. Some races were more advanced, closer to feudal Japan or China. Elven races with space travel and/or electricity are few in number, but do exist.
• Societal structure. If even a tenth of the elven kings, queens, princes and princesses out there are genuine, we can assume that most elves had a penchant for large monarchical systems of government. Population is usually distributed in small tribes or communities, with cities serving as centres of commerce and government. In this respect, many elven societies are vaguely reminiscent of mediaeval European cultures.
• Culture. Most elven races are famous (or infamous) for their love of wine, women (or men) and song. Elves are great lovers of the arts and of intellectual pursuits, and so many of them end up as geeks and neophiles while here on Earth.
• "Subservience." Many elves seem to thrive when they are helping people out. This, in combination with their aforementioned love of royal hierarchy, has in some cases earned them the reputation of being subservient. It is probably more true to say that they devote themselves to the people they care about, but are perfectly capable of standing up against people who cross them.
• The Corruption. If all reports are to be believed, a force similar to the "Nothing" from the Neverending Story managed to effect a vast number of elven worlds, and even destroyed some of them entirely. This really deserves an article all to itself.