All Bleach characters are souls. Living humans contain souls within their bodies. Disembodied souls, spirits, have a form composed of particles of spiritual energy called ectoplasm, with an anatomy similar to an ordinary flesh body. This form encompasses all of the spirit's being; there is no distinction between mind and body. Specific character types are described below.

Humans:

The humans of Bleach are much like the residents of modern Japan. Most humans cannot see or sense spirits in any way. However, souls can inhabit artificial human bodies that are visible to ordinary humans. One in 50,000 humans is a medium with some awareness of nearby ghosts, but only a third of these are able to see them clearly. Some humans naturally have both the power to sense and the strength to fight with spirits. Other humans can gain the ability to do so by spending time around a large source of spirit energy.

Plus:

Benign ghosts in Bleach are known as pluses (Wholes in the official English editions). A plus is the spirit of a person who has died. A chain, known as the Chain of Fate, protrudes from the chest and binds the plus to a location, object or person that they felt close to in life. The soul can move about freely if the chain is broken, but this also causes the chain to corrode. Normally, pluses are sent to Soul Society by shinigami in a ritual called soul burial before this corrosion becomes significant. However, if the Chain of Fate is corroded entirely before a soul burial can be performed, a hole will form in the chest of the soul where the chain was once anchored. Such souls are driven mad and become evil ghosts known as hollows. If the Chain of Fate is torn out deliberately, this also leads to spiritual degradation.

Shinigami:

Shinigami (Soul Reapers in the official English editions, Death Gods in most subtitled versions) are the psychopomps of Bleach. They are souls with inner spiritual power, recruited from the ranks of the residents and nobility of Soul Society. Like all spirits, they cannot be detected by normal humans. Shinigami use their soul slayers (zanpakutō) to perform soul burials on pluses. Shinigami also use zanpakutō and demon arts (kidō) to fight their archrivals, the hollows. Some shinigami have acquired hollow powers using illegal methods; they are known as the vizard.

Hollow:

The hollows are the major antagonists of Bleach. They are evil ghosts who reside in Hueco Mundo but travel to the living world to feed on the souls of the living and dead alike. Like shinigami, hollows are made of spiritual matter, cannot be detected by ordinary humans, and use their internal spiritual power to fight. While most hollows can be overcome by the average shinigami, some can surpass a shinigami captain in strength. All hollows wear white masks, except for a few called arrancar that have been able to remove most of their masks and tap into the powers of the shinigami. Although they carry zanpakutō, the sword is used to modify the body of the arrancar itself. Tite Kubo has used a Spanish motif to name hollows and arrancar throughout the series.

Artificial Souls:

Artificial souls are a type of soul mass-produced by the shinigami. Issued in pill form, they are used to to force a shinigami out from his gigai during protracted stays in the living world, and come with a pre-programmed personality that animates the shinigami's body until his return. In addition to the mundane versions, a series of experimental souls authorized and created by shinigami researchers also exists. Known as modified souls, these were meant to hunt hollows by possessing soul-less human bodies and supercharging a particular aspect of them (for example, strength or speed). The shinigami decided to scrap the project due to the inhumanity of forcing dead bodies to fight, leading to the destruction of all modified souls. Those that were manufactured but had yet to possess human bodies were also to be terminated, but some escaped. The only modified soul in the original manga is Kon. In the anime, however, three others live in gigai created by Kisuke Urahara.

Quincy:

The Quincy were a clan of spiritually aware humans who once fought against the hollows, using weapons composed of spiritual energy to slay them. As opposed to shinigami, Quincy absorb and channel energy from their surroundings. When a shinigami slays a hollow, this cleanses the hollow's soul and washes away its sins, allowing it to enter Soul Society. The Quincy technique to slay hollows simply destroys the soul entirely. Furthermore, using this method has the propensity to shatter the balance of the universe. When souls are destroyed, the number of souls entering and leaving Soul Society cannot remain equal. This issue prompted the shinigami to conduct a campaign to exterminate the Quincy about 200 years before the main storyline. However, at least two Quincy remain.

Bount:

Introduced in the anime, the Bounts are, like the Quincy, a clan of human beings with high spiritual energy and special powers. They were accidentally created by shinigami scientists looking for a way to create eternal life. Bounts consume the souls of human beings to survive; theoretically, a Bount could live forever by doing so. Although the Bounts have a strict rule to consume only the souls of the dead, the final group of Bounts has chosen to drain souls from living humans in order to become more powerful and destroy the shinigami world. Each Bount uses a "doll" in combat, a type of familiar possessing its own special abilities. Every doll is unique and is a manifestation of the user's power. If the doll is destroyed, its owner is destroyed as well.