Eladrin, elves, drow, and orcs are one race, sometimes called the Eldar - that is, they share common ancestry, and a common home archiepelago - long, long ago. Compared with almost all other civilized lands, the Eldar homeworld is far more feytouched and mythic; time proceeds differently there, the Fey are common, close-by, and nearly comprehensible, and magic works differently enough that class-based powers of almost every sort are strangely and unbalancingly different: arcane is unpredictable, primal is strengthened, divine, infernal, and primal are all weakened.
Eladrin
The eladrin have a civilization that has stood for thirty thousand years: they explore but do not colonize; they treat all things with respect. But they meddle, when it suits them, in the affairs of others, and have a quiet arrogance that they know best, even when they do not explain themselves.
Eladrin sailing ships range from richly decorated but mundane vessels up to glittering, impossible constructions that resemble spun sugar and seem more to pass lightly through water than sail upon it. It is believed their scholars know more of the reality of Ia than any other race.
Eladrin and elves are not overtly hostile toward, nor indeed profess much of any feeling toward, one another; they simply prefer not to deal with each other at all. Eladrin have tremendous antipathy toward drow, and affect not even to notice orcs.
Elves
Compared with eladrin, elves are more wild, more adventurous; they behave more as a younger race, but with a tendency toward personal distance that derives from their deep, mystic connection to nature. Their sailing ships appear to be organically grown (and often are).
Elves have no central government or hierarchy beyond their forest cities. They are more likely than other civilized races to be pirates, but their pirates are more likely to minimize body count and manage prisoners and ransoms. They are also more likely than other races to rescue those in distress, or provide unappreciated (and often unnoticed) wilderness security for the cities of other peoples. Elves are also often conquered and made into slaves, due to the lack of any government to demand restitution or retaliate.
Having no hierarchy of government to speak for them, elves do not make war and seldom claim archipelagi for themselves - however, as a culture they do not recognize property rights to whole islands, and make colonies and villages in deserted areas (typically forests) wherever it suits them, often leading to conflict when these colonies appear without the permission of others living previously on the same island. They hire as mercenaries often; they also often take service on vessels of other (non-Eldar) races. Because they are found in the wild more than other races, they can be hunted by the intolerant and enslaved by the belligerent: a slave galley will typically have elves interspersed with hobgoblins, orcs, and humans.
Alone among People, elves seem, occasionally, to make a connection to the islands where they make their home that resembles the connection other races have to their home archipelago.