Fae are one of the four dream races and are material and permanent. On the surface Fae appear very much like mortals but their behaviour is limited by geis. It is almost impossible for Fae to speak untruths (they are allowed to be mistaken but direct deceit is beyond them). Although Fae are not bound by geis as thoroughly as Spirits every time they violate a geis they suffer physical damage. Enough of this can disperse a Fae into chaos.
Although the apparent method of procreation for Fae is the same as for Mortals (and many Fae can indeed procreate with Mortals producing halfbreeds) the biological processes come second to the complex web of geis which surround the mating process. Add together the natural problems of mating with the geis that surround successful mating and the birth of new Fae is very rare.
Because of this Fae prize children above all else. Fae themselves are potentially eternal, although they can be dispersed into chaos or imprisoned using constraining geis.
Of the two methods of disposing of a troublesome Fae the latter is easier but the former is harder to escape. Neither method can truly destroy a Fae, the only things that can destroy Fae are agents of the Dream and the Void.
A Fae child grows at a rate entirely dictated by their own evolving personality. Some are children a short time and others for centuries.
Upon birth a fae child is given a number of "birth geis", laws and restrictions which they must abide by. Although the heaping of seemingly arbitrary rules onto the life of a newborn may seem cruel in truth newborn fae without such restriction often dissolve into chaos. Technically a child who dissolves this way is not dead, but their energy is so diffuse that it is almost the same. Fae children lost this way can reform spontaneously under certain conditions (often dictated by geis which come from those who sense the latent energy, or are placed upon the energy by itself during brief flashes of lucidity) when their essence has been restricted and shaped enough to become a seemingly random formation of life. What congeals out of the chaos is never a child but always some bizarre mostly chaotic intelligence. These beings are feared by Fae as they are often quite familiar with manipulating chaos and find it easy to disperse those who oppose them.
Once a Fae creature has grown to maturity it looks forward to an eternal life punctuated by periods of dispersal and constraint. To cope with the long periods in which a Fae has no material or substantial aetheric presence with which to gain any sense of agency Fae are limited in imagination and feeling. Fae have the ability to "store" phenomena such as colours, smells, sounds, emotions, tastes, preferences so that they can be experienced in the absence of physicality. The stored items are removed from manifestation elsewhere in the dream; hence the trade of the "Goblin Markets" which offer boons and trinkets in exchange for little nuggets of individuality that dispersed or constrained Fae may find a brief diversion from senseless oblivion.
Although Fae creatures live forever their lives are filled with rules, regulations, conditions, promises, bargains and obligations all of which make a heavy burden for those that choose to participate in the life of the four worlds. Most creatures with some Fae nature are actually half-fae, blendings with Mortals or Jin. Half-fae live between four centuries and several millennia years depending on their exact nature. They often are subjected to some geis but also have a little free will.
Fae societies are not at all dynamic, the Fae are an unchanging species and their societies reflect this. The Fae worlds almost exclusively connect to static Mortal worlds and the Spirit plane. This is not to say there are no direct routes to dynamic Mortal or Jin realms but these pathways are few and most are zealously guarded.
The Fae refer to all of their realms collectively as Faerie although these realms exist on multiple interconnected planes some of which are stacked on top of one another. To the Fae all the ins and outs of the dream are irrelevant, anywhere that is mostly populated by Fae is part of Faerie.
This attitude is partly fuelled by the general Fae extreme conservatism. Anyone a Fae has not known since birth is generally mistrusted as a stranger, anyone not Fae is a stranger. Fae don't like strangers. To a Fae a stranger is a bundle of potential inconvenient geis that just hasn't resolved yet.
Fae find it very easy to be cruel and are shallow in their outlook on the universe. In Mortal terms almost every Fae is a high-functioning sociopath looking out for themselves with utter disregard for the feelings of others and with no concept of empathy or sympathy.
For this reason Fae have the potential to be immediately appealing, funny and attractive. They do not mind being a sinkhole for the obsessions of the more emotional as long as they can just cut and run at a moment's notice.
Fae simultaneously crave order and despise it. Without order Fae disperse but every new geis blunts what free will a Fae can lay claim to. All Fae are bound by a necessity to be as truthful as possible at all times. For these reasons Fae are particularly prone to personal insanities that can last for millennia, sane Fae are intensely political and mercenary, it is usually the weight of their constant scheming that makes them break down.