Mortality

In the Arcane Realm, a variety of creatures have an interesting variation in their lifespans. Society has developed terms to group those who live and die in a similar manner.

On Aging

Aging is a complex process that can be best defined as "a progressive deterioration of physiological function, characterized by the declining ability to respond to stress, increased internal imbalance, and vulnerability to aging-related diseases and conditions." Different species age at different rates which reflects on how different people groups value certain things over others or how they can value the same aspect in different ways.

On Death

Death is the end of life and the ultimate result of aging and a defining trait of being mortal. It should be noted that aging itself isn't the cause of death, that goes to age related diseases such as organ failure or cancer.

Variations of Mortality

Due to the variety of lifespans among the races, the simple mortal-immortal dichotomy made less sense as time when on. As such, society moved to understanding a spectrum when it comes to mortality that is explained below.

Mortal

"Mortal" creatures are those that have a clearly defined aging process where they are born, grow until a species specific reproductive period usually called the adult stage. Then after that stage, the creature will typically suffer the gradual deterioration that results from aging. Mortal creatures have comparatively higher rates of reproduction to counteract death rates. 
Mortal creatures include seasonal and annual plants, most animals including humans and most henge.

Semi-immortal

Semi-immortals are creatures that grow into reproductive adults like mortals but don't ever seem to reach a point where their bodies deteriorate from aging. As such they usually stay within their physical prime for as long as they live. It should be noted that they are still susceptible to death from means other than age related diseases. In fact their are multiple types of semi-immortality.
Biological Immortality/Ageless includes

Body doesn't deteriorate over time

Indefinite lifespan

Remains vulnerable to mortal wounds, diseases, and foreign substances.

Vulnerable to mental stress that can deteriorate body of being.

Common to perennial plants, biologically immortal animals, fay, nature spirits, jinn spirits, minor demons

Regenerative Immortality is when a creature has a high level of body regeneration that repairs the body faster than it can degrade, eliminating practically all signs of aging. Their regeneration is usually enough to heal from injuries, even fatal ones and prevents one from dying in many cases. Although this is a prized form of immortality their are limits that prevent true immortality. 
-Long term exhaustion and injury (to the point of death) can be inflicted if cellular damage to occur faster than the rate of regeneration. -While immune to most diseases, toxins and drugs, eventually a select few can overtax or counteract a creatures healing mechanism.  -Specific methods of death always seem to override this such as suffocation, predation, etc.  -Regeneration usually requires additional energy or material and will fail if reserves are too low. -This is specific to fay, jinn and nature spirits, minor divinities, ascended henge like drakains and high ranked jiuweihu mid tier demons including succubi.


Retroactive Immortality is an interesting an very specific form that is mostly uncommon.

Being can die but doesn't remain dead, always resurrecting or reincarnating oneself after being killed.

May take a while to revive.

Typically occurs only for minor divinities, major divinities that are incarnated, or through very specific rituals, mainly ones related to either necromancy or thaumaturgy. 

Reliant Immortality

This is an artificial form of immortality acquired by anchoring their life to a certain object, source, concept, etc.

Destruction of anchor ends the user’s immortality and returns mortality.

May require continuous intake of source or maintenance of object to remain immortal.

As it is artificial, it requires certain magical items or rituals or can be found in certain types of undead

Immortality

True immortality is the inability to die or be killed. This is extremely rare and only though to have been possessed by the deities of ancient religions as well as the transcendent deity of Suffah  and Ecclesiam

Type

Physiological