If there's any more questions that this doesn't answer, I can try to answer them as well.
Soul Information
Mortal Sins-Negative actions that human has not paid penance for in human life and corrupt soul and make them become a Hollow much quicker
Plus-Human soul that is still attached to human world. Is sent either to hell or Soul Society by soul burial. Destination is determined by mortal sins committed as human. When Plus is in Rukongai, they are never hungry, only requiring water to survive and when they become hungry, it means that they possess spiritual powers.
Chain of Fate-Chain that keeps Plus soul attached to human world and human body. Once it breaks and degrades completely, Plus becomes a Hollow. Chain will begin process called corrosion after it is broken, consuming itself slowly. This process can take any number of hours, days, weeks, months, depending on the nature of the soul. With the end of corrosion begins the transformation to a Hollow. If one can overcome this transformation, one can in theory gain Shinigami or spiritual powers otherwise, but this does not mean the soul cannot return to the body, as Shinigami souls can still enter the original body.
Hakusui-Soul Sleep. Located where the heart is in a human boday. Holds the key to spiritual abilities in a Plus or Shinigami soul. Enhanced by the chain link, which boosts spiritual abilities. If this is destroyed, then the spiritual power eventually disappears and when combined with the destruction of the Saketsu, generally spells death for the soul, making them a normal human after rebirth and even if the soul survives these two aspects of the souls destruction, spiritual power is utterly lost and it becomes a normal soul.
Saketsu-Chain Link. Located right next to Hakusui. Booster of soul sleep, allowing the soul to use spiritual powers in the first place. When this is destroyed, spiritual power is damaged greatly and when combined with the destruction of the Hakusui, generally spells death for the soul, making them a normal human after rebirth and even if the soul survives these two aspects of the souls destruction, spiritual power is utterly lost and it becomes a normal soul.
Hollow Information
Demi Hollow-Earth bound Plus that is on its way to becoming a Hollow. Certain things in the humans life are binding it to the earth and it eventually is overcome with grief and sorrow, transforming into Hollows and reappearing in a new place than before.
Hollows-Evil spirit that eats other Pluses, especially highly concentrated spiritually aware ones. If Hollow is defeated by Shinigami and hasnt committed any mortal sins, they are sent to Soul Society. If Hollow is defeated by Shinigami and has committed mortal sins, they are sent to Hell.
Shinigami Related Information
Shinigami/Soul Reaper-Agent of the Spirit King. Manages the balance of spiritual energy
between Soul Society and the Human World. Also manages spiritually aware humans, Hollows, and other spiritual issues
Zanpakutou-Soul Cutter. Blade that is able to perform konsou (soul burial ) on Plus Souls and purify Hollow souls and send them to Soul Society, or to hell depending on the purity of the soul. Manifests powers depending on the Shinigamis spiritual abilities and concentration, etc. After gaining a communication level and expertise over the Zanpakutou spirit within the blade, one can manifest Shikai, initial release, the first level of power. Once the Shinigami can manifest the Zanpakutou spirit in the physical world outside the Zanpakutou Inner World and dominate and control the Zanpakutou spirit, they can achieve the full release of power of the Zanpakutou, called Bankai
Spirit King-Manages the balance between Soul Society and Human World. Manages Rukongai and Seireitei with the aid of the Shinigami and the Council of 46 through an inner realm of Soul Society outside of Seireitei and Rukongais physical existence. Protected by the Royal Guard
Council of 46-Manages Shinigami affairs and incidents that cause an imbalance of spiritual energy, including Quincys and over abundance of Hollows.
Planes of Existence
Living World-Humans and Quincy keep residence here. Some humans are raised as Quincy, enhancing their ability to dominate and control spiritual energy around them, able to destroy Hollows with their powers, which causes an imbalance of spiritual energy while some humans are merely spiritually aware and have a great deal of spiritual energy that attract Hollows
Rukongai-Where any human souls live that dont later become Shinigami. Appear and live in Rukongai in the form when they died, be it a child, an adult, or an old person, they stay in that form until they pass on and are reborn in the Living World.
Seireitei-Where Shinigami live and are trained, keeping residence there, etc.
Soul Society-Area where all souls keep residence in one place or another. Composed of three levels of existence. Rukongai, where basic human souls keep residence. Seireitei, where Shinigami are trained and keep residence and watch over Rukongai and the Living World. The third level is hidden from the Shinigami and Gotei 13, where the Spirit King and the guardian force of the Spirit King reside, keeping watch over Seireitei and through them, a watch on the entire world by virtue of the web of connections that exists.
Hell-Area where corrupt human souls are kept prisoner and punished for mortal sins accordingly by the ruler of hell, Enma. Is separate from Soul Society, closer in spiritual location to Hueco Mundo.
Hueco Mundo-Area where Hollows exist that have not been defeated by Shinigami or Hollows. Having been in existence for quite sometime, possibly as long as Shinigami or longerm the Hollows have developed a hierarchy of existence that determines power and authority.
First there are the lowly Gillian ranked Hollows, who have recently transformed and are still more monster than humanoid in any shape, subservient to the higher ranked Hollows. Next are Ajuukasu level Hollows, who have lived a bit longer and have developed further intelligence and power, rarer in the grand scheme of Hueco Mundo, older than the average Hollows, surviving by various tricks. Lastly are the Vastoroode rank who have manifested a human shape and are stronger than even many of the strongest Shinigami, having lived for many centuries. There are also Menos, who are a manifestation of many Hollows merging together as one.
Other Spiritual Devices and Concepts
Spiritrons-Raw spirit energy found in the environment. Easier found in rural wilderness areas than in urban areas. Also, in Soul Society, everything is made of spiritrons, being a spiritual world completely, physical beings unable to enter without a spirit transfer device
Gigai-False body used by Shinigami to slowly regain their power after especially difficult nbattles. Allows them to blend in with human population while they are recovering as it resembles a human very clearly
Gikongan-Also called Soul Candy, it carries a soul within it that when ingested by a Shinigami in a gigai, forcefully ejects them out of it, releasing their soul and allowing their body to be taken over by a replacement soul.
Kiokuchikan-Memory Replacement Device that replaces the memories of spiritually sensitive humans, so that they do not recall the existence of Shinigami or Hollows, keeping the humans unaware of the spiritual world.
Jigoku Chou-Hell Butterfly. Allows Shinigami to pass between worlds, also serving as a messenger to officers in the Gotei 13