The wood elves, known among themselves and their dark bretheren as Quelari, are a kin of the ancient race of Eldari, whose fate is among the most tragic of all peoples who surivived the Planetfall. With a tentative blessing of the Fair Queen of Fey, the Quelari dig their burrows deep within the deadly forest of Gwynwald, entrenched in a centuries-long genocidal war against Quenn Ulthar.
Biologically, all elven kin - Quelari, Ulthari and Allavi - are the same, having once been the united Eldari. Whatever differences in disposition, build and skill that they inherently possess come from their different upbringings and circumstances of life.
All elves are technically immortal - if they do not succumb to violence or accident. The legends of men tell us that even after death, their souls return to the mortal realm, given new life either as incorporeal spirits or reincarnating into an elven newborn. The elves themselves, however, are notoriously secretive about this trait of theirs.
It is possible for an elf to lose its will to live on and rapidly fade away - usually in response to life-shattering tragedy or horrendous violence. A consequence of this is that it's pretty much impossible to successfully torture an average elf - they will fade before anyhing useful can be extracted from them.
After the great shattering of the Eldari, the faction that would soon be known as wood elves rallied around their ancient loremasters and priests