Cosmology

Cosmology is the study of the universe, but in this sense it refers to a fictional universe, and how it all fits together. 
Part our world, and part mockery, the world of Darkness consists of various "planes" or dimensions of existence, where various denziens can exist. 
==Pandamonium==
Like all the Supernal Realms, the exact nature of Pandemonium is somewhat subjective. The most common realm experienced by arriving Mastigos is that of as vast network of caverns, without end or outside, populated by a horde of unruly deformed creatures; the demons of Pandemonium. This great maze has no true beginning or end, but winds on and on through throngs of madcap beasts, stretching on into eternity. The pathways and passages inconstant; they shift from visit to visit, but there are some stationary features, although they shift in size, shape and appearance; these are demon kingdoms. Their exact nature shifts, their theme remains invariable for those who can see them for what they are; the kingdoms of the seven Vices. (Read Dante’s Inferno to get a good idea about these dominions).
Pandemonium is often compared to the idea of the 'shadow' of the collective subconscious, a place of rejected ideas and fallen ideals. Thus, the demons of Pandemonium are identified by scholars from other Paths as dark reflections of creatures native to their Paths; fallen angels, Unseelie Fae, rabid beasts, evil spirits or malevolent dead, dark matter gargoyles; others think the realm is a vision of a possible future; a mass Awakening of humanity without the necessary mental discipline. Each demon is viewed as human wielding power beyond their understanding and control, their darkest desires and basest urges expressed through their unWise use of magic.
Many mages view the Supernal Realms as stages along the soul's journey to absolute transcendence, vital steps that must be taken before ascension to the place beyond the Fallen and Supernal Realms. If this is the case, then Pandemonium is the place of penitence, where souls are purged of its sins, derangements, cares, obsessions, and attachments to the material world. The moment the soul arrives in this realm, packs of demons descend on him/her, screeching and clamoring with joy as they tear them apart. This torture is not malicious in aspect, though the demons seem to enjoy it; they are a form of spiritual surgery, a way of cutting out the bad parts. There is no anesthetic for this surgery, no peaceful sleep while the fiends do their awful work; the victim has lived too long in ignorance of the pain he has caused others and must now feel its full force. Without this the soul cannot have empathy, nor share in the souls of others, so cannot rise into true until with them.
Pandamonium is the direct source of individualism, and hence the direct source of the Mind Arcanum, but harder yet to understand, it's also the place where people go to dream. Litterally. Every living persons mind is represented as a place of infinite space there and a place of infinite direct source of the concept of space. 
There are a number of theories amongst the Warlock as to why their power over Matter is diminished. Some believe that it is due to the lack of metaphysical weight in the Realm to contain or obstruct one's actions. Others think that matter is seen as inimical to demons because it is the only thing that can bind them, and that it’s not present in Pandemonium. Still others theorize that Pandemonium is 'denser' than the other Supernal Realms, and this weight draws it closer to the Material Realm; thus, some of the Material Realm's laws act on Pandemonium. Mastigos cannot easily manipulate matter, as this theory would have it because the Realm is partially affected by laws of Fallen World matter. Whatever the reason, Mastigos cannot easily wield the Arcanum of Matter.
==The Shadow and the Primal Wild==
The Shadow or Shadow Realm (Hisil in the First Tongue) is a separate, animistic plane of existence composed of ephemera and inhabited by spirits.
The Shadow is a warped reflection of the physical world (or Material Realm) in which everything is alive; anything of import that happens in the Material Realm may birth a reflection in the Shadow, and that reflection may live on long after the original is gone. Thus demolished buildings, ancient trees and extinct animals may all still exist there in spiritual form, as may ideas and concepts which pre-date anything in the modern world (among which are the idigam). The only exception are human beings (and similar creatures like vampires, werewolves and Prometheans): people are eerily absent from the Shadow. This may be because only these creatures possess souls (or, in the case of Prometheans, an equivalent). (Ghosts, the echoes sometimes left behind when humans die, are composed of ephemera but exist in Twilight, not in the Shadow.)
Travel between the Material and Shadow Realms is impossible because of a barrier known as the Gauntlet, except at places of great spiritual energy known as loci. Because of the Gauntlet, few mortals are aware of the Shadow; only spiritual creatures, Uratha, mages adept in the Spirit Arcanum and Prometheans of the Ulgan Lineage commonly interact with it and its denizens.
According to the lore of the Uratha, the two realms once intermingled much more freely. It was Father Wolf's task to patrol the border between the realms, keeping a balance in the affairs of mortals and spirits. When Father Wolf was slain, the Gauntlet rose between the realms. The Forsaken Uratha of the modern world have now taken on Father Wolf's role, ensuring that the denizens of the Shadow Realm do not meddle too much in the Material Realm.
To mages, the Shadow is part of the Fallen World and the Realms Invisible.
The Primal Wild is something that exists, making travel in the Shadow incredibly difficult.
The realm of the Primal Wild is, as the name would suggest, a vast and uncharted wilderness. All the unclaimed places of the Fallen World have their analogues in the Primal Wild, each ecosystem recreated as an exaggerated version of how it is in this World. Though the life forms appear the same, the scale is vastly different. Trees seem far taller, beasts much larger, terrain more treacherous and weather more powerful. The realm is not exactly hostile to humanity, but discourages humanity’s complex thoughts; here, the raw emotion of the animals and the strange, linear intelligences of the spirits hold sway. All material wildernesses are reflected in the Primal Wild, but none on such vast scales as the jungles and the oceans.
The jungles of the Primal Wild are perhaps the most powerful representation of Fallen World ecosystems. Despite their infinite variety and majesty, their equivalents in the Material Realm do not come close to comparing. For each subspecies of creature the Fallen World has to offer, the jungle of the Primal Wild vomits forth one hundred, each more bizarre to the human onlooker than the last. These denizens of the jungle all want their toll in blood, even the trees and vines, for blood is the currency of the Primal Wild’s jungles; all have their own means of obtaining it. All creatures are enhanced beyond the limits of their Fallen World counterparts; predators are stronger and deadlier, prey are faster and more numerous. Visitors to the jungle – meaning every Thyrsus mage in existence, as this is where the Watchtower of the Stone Book can be found – report their feelings of fear and vulnerability heightened to maddening degree - but so are their passions and lusts, for the madness of the Primal Wild inspires as well as terrifies.
The Primal Wild’s oceans are similar. Humanity’s fear of the first time being in a vast body of water is well known; the roar of the waves as they play with the swimmer, tossing them about, crashing against them, or relentlessly pushing them under, inspires feelings of helplessness and insignificance in many mortals. So much greater is the ocean of the Primal Wild that many get these same sentiments merely looking at it. The moon’s call is greater here, so the tides are too; the waves hurl themselves against the shore with a ferocity that makes many think of titans in battle, a self-aware phenomenon as much as anything else. This is partially true; the power of the spirits in the Primal Wild is undeniable, and the open ocean plays host to war games between great gods of storm and surf, using hurricanes and rogue waves as toys and weapons.
So, as it would appear, the primal wild is something that slowly errupts all around the places where humans do not tread, but in the Shadow world, that is. 
Spirit Magic, and Life magic stems directly from this realm. 
==Stygia==
What is Stygia? Stygia is the realm of the dead. Everything there is made of a strange substance known as ectoplasm. Black Magic comes from this place, from this realm, and it's one of the strongest and most potent sources of magic available. Stygia, for obvious reasons, remains the most unknown realm of them all. It's believed to be the prison of several spirits that have grown too powerful and were banished there, these spirits known primarily as demons, while every soul of everyone dead travels here. 
Black magic is considered the inferior arcana of everyone not awakened in the realm of Stygia, and despite people awakening in Stygia being directly tied to only one kind of magic, there is great power in exclusiveness. Only a select few mages will know how to properly defend against black magic, and true mastery of Black Magic is extremely rare, making the few people who do master it to such a degree quite important. 
==Arcadia==
Arcadia is a realm of constant change. The weather, the landmarks, even the geography is never the same per visit. Each Acanthus reports different features through which they must travel to the watchtower upon their Awakening. Mostly, the physical features of Arcadia are similar to those of the Fallen World, but taken to extremes. Great mountains, vast oceans, deep caves, fetid swamps, and plains and deserts that seem to stretch on forever are commonplace, but these features are transient. Rivers change their courses at will; mountain ranges rise up and erode over night. Only two features are known to be constant, and only one is ever in the same place for any length of time. The source of the Alphaeus River, though it’s always around somewhere, that place changes frequently. The second is the Watchtower of the Lunargent thorn, its always at the center of the realm however the that center has been known to shift around from time to time.
The weather in Arcadia is even more fickle than the land. Storms form up out of a clear blue sky; F-10 tornadoes spin up out of nowhere, accompanied by earthquakes at least 10.5 on the Richter scale. These conditions disappear as soon as they come; giving way to skies of blazing azure with light, cool breezes. Droughts and floods, rain and snow, gales and storms each occur in places on a regular and disorienting basis. Time is as temperamental and unpredictable as the weather; there is some Acanthus who believes that the rapidly changing weather can be attributed to the fluctuations of time that move across the realm like the very storms themselves. Stories of people going to sleep in an isolated part of the wilderness only to wake up decades later, (i.e. Rip Van Winkle) probably stem from contact with the realm of Arcadia.
There is one element in the entire realm that is absolutely permanent, that element is the power of the spoken word. Words uttered in Arcadia have a great and terrible power, and the realm can exert this power over those who put their foot in their mouth or intentionally break a promise. So in other words lying and breaking your word will guarantee a penance until you admit your lie, or keep your word.
It's the realm of chaos, fate and time are the only factors that matter in this realm, and also where those two arcana come from. The only creatures known to reside in Arcadia are the fae. 
==Aether==
The aether is a realm of matter and energy very similar to the material world, except devoid of life. Barren world of mountains and abundances of material everywhere, with lightingstorms and terrible wind. Matter/forces aracana stems from this place. 
==Astral Space==
The realm of pure creativity and oppertunity. It's the realm of possitive energy. It seems to be the source of new souls, and also the place from which essense actually bleeds over into the spirit world, after being unleashed by the material world. This world is the source of prime magic. Prime mages have Death magic as their inferior arcana. Prime is as powerful as it's counterpart, but is less ill-regarded, as it's primary use is to create magical artifacts and to bind other spells, not to destroy. Using prime as a destructive force is difficult. 
==The Abyss==
Having many names, the abyss is the negative zone that seperates all of these realms from eachother, almost entirely, allowing them to only connect in the form of the material world. The Abyss, can appear in many ways, and it seems there are many layers of it, one of them being the "hedge", another being the twilight zone.