Originally thought to be from an entirely different world, fairies are incredibly mysterious. Most of what is known of them is from first and second hand accounts by humans or nephilim. Fairies are neither good nor evil, they simply act and do as they please. There are many different categories of fairies, so we will be sticking to general characteristics and abilities the majority of them possess.

Identifiers: fairies/fay are typically humanoid creatures with animal or plant identifiers that possess wings and have pointed ears, along with natural, unusual hair colors. They often have light or deep melodic voices no matter the gender (or lack thereof) and range from either precious cinnamon roll innocent or demonic levels seductive/manipulative. They have a deep connection to nature and either live in/near forests, mountains, etc. or if they live in cities (disguised of course) their home will be bursting full of plants and fountains. They tend to work low effort yet specific jobs and get a lot of money very quickly one way or another.

Powers/Abilities: They have superhuman strength and durability and possess the ability to shapeshift and/or produce glamours, often either used to blend in with surroundings or look human. They also possess healing abilities, chlorokinesis (ability to grow and control plants), oneirokinesis (ability to control and enter dreams), telepathy, and mesmerization (hypnotism). There is also the power of oath, in which if the promiser breaks the oath they will die in painfully hilarious ways.

Weaknesses: Lemons, limes, and poisonous bugs are highly toxic to fairies, and sunglasses/no eye contact negates mesmerization. Silver burns dark fairies (fairies that have become corrupted & lose their natural color and purposefully seek to destroy nature and harm other species, including their own) but doesn't do anything other than annoy normal fairies, though iron bothers both.

Properties of Fay Blood: Fairy blood, when consumed by vampires, often results in the vampires getting intoxicated, and in the case of a pure blood, temporary immunity from sunlight. Fairy blood is also very attractive to other supernaturals and is often used in spells.

Political/Societal Stuffs: The way their society works is still a mystery, but is to be thought as similar to a aristocracy, though this of course is depending on the kind of fay. There are two main courts- the Seelie Court (benevolent) and UnSeelie Court (malevolent).

Mating: Fairies can mate with any species. They can either have life long relationships or simple flings.

Offspring: Fairies can reproduce like any other creature, but also have the ability to reproduce asexually.

Lifespan: fairies/fay age much slower than humans, so their lifespan ends up being exponentially longer. One of the eldest known fairies died naturally at approximately 20,000 years old, so the life expectancy is 15,000-20,000.

Some Known Categories:
Fairy- the winged humanoid creatures we tend to think of
Sprite- an elemental ghost-like entity that appears as a loved one with wings.
Imp- often the michevious offspring of demons and fairies
Brownie/Broonie- a household spirit that comes out at night while the owners of the house are asleep and perform various chores and farming tasks.
Elf- tall, graceful humanoid creatures known for hunting and healing, as well as their magical abilities (are wingless/flightless).
Changelings- a type of human/fairy hybrid, often used to replace stolen human babies as they can take the approximate shape of the child, however they often become sickly or malformed for reasons unknown.
Dwarf- usually depicted as shorter, stockier, hairier than humans, they are usually associated with vast hoards of treasure and blacksmithing.
Troll- the cousin of the Dwarfs, they are known for how they turn to stone in the sunlight and for being guardians of passages and bridges.
Goblin- a term traditionally reserved for an ugly fairy that is either mischievous or malevolent.
Leprechaun- short humanoids with their appearance varying on their location, these fay are associated with fashioning and cobbling shoes, as well as hiding their money in pots at the ends of rainbows. They are quite the greedy and clever creatures, and it's very rare to outsmart one.
Centaur- humanoid creatures with the top half of a human and the bottom half of a quadrupad animal, typically horse,though this changes with the environment of the centaur.
Kelpie- a malevolent water horse spirit that can take on a human or elf form, often takes delight in drowning people. It is said that if you tame a kelpie you will never die from drowning and will be highly respected in the fay community.