Information storage devices known as Holocrons were employed by both the Jedi Order and the Sith. These devices housed ancient teachings or precious data in a holographic format. Their physical form consisted of palm-sized, radiant polyhedrons composed of crystalline substance and integrated hardware. Activation and utilization of these devices were exclusively achievable through the power of the Force.
These Holocrons were small enough to be held in one's hand and served as data storage units. A great number of them were uniformly shaped polyhedrons, constructed with crystalline facets. Select models featured see-through outer casings, granting users a view of the internal mechanics, and they emitted light upon activation. The Jedi-constructed ones were often cubes, cuboctahedrons, or dodecahedrons, such as the Great Holocron. Conversely, the Sith-made versions took the form of pyramids or tetrahedrons. Functionally, they mirrored their Jedi counterparts, safeguarding the age-old secrets of the dark side and the Sith Order. The holocrons crafted by the Dai Bendu housed their own unique doctrines. Despite sharing similar functions and appearances with Jedi holocrons, they differed in accessibility, being usable even by individuals with minimal Force-sensitives abilities.
Holocrons functioned as secure containers for critical and sensitive knowledge and wisdom related to the nature and application of the Force, a mystical energy field that binds all living beings throughout the galaxy. The information was typically presented as an interactive hologram that resembled the individual who originally recorded the data. Given the delicate nature of the lessons they contained, many of these devices included a security feature that restricted access to those with a strong attuned connection to the Force. Furthermore, numerous holocrons required pairing with a specific memory crystal for activation. When the Force was properly applied to unlock a holocron, it would physically manipulate its internal components, granting the user access to its stored information. Each of these components was imbued with the Force's power and retained a degree of functionality even when detached from the holocron, such as the ability to remotely manipulate data from another holocron or locate Force-sensitive individuals.
In the event that a Jedi holocron and a Sith holocron were simultaneously opened by a follower of the lightsider and a follower of the darksider, a fusion would occur, enabling them to answer any question posed by the users. Holocron fusions were exceedingly rare due to the unlikelihood of a light side user and a dark side user collaborating, and by the time of the Galactic Civil War, knowledge of this practice had largely been lost.
The Dai Bendu, considered the forerunners of the Jedi, are credited with creating the earliest holocrons.
Throughout the centuries, the Jedi created hundreds of holocrons. Recognizing their historical importance and the invaluable knowledge they contained, the Jedi stored these artifacts in the Great Jedi Library on Ossus and within the Archives of the Jedi Temple on Coruscant. The most prized specimens were kept under lock and key inside the restricted Holocron Vault.
During the Clone Wars, Cad Bane orchestrated a daring heist to pilfer one of these artifacts from the Vault, specifically the Kyber memory crystal. After Darth Sidious established the Galactic Empire and initiated the Great Jedi Purge, holocrons became uncommon relics of a bygone age. Nevertheless, Imperial operatives trained in the dark side of the Force, such as the Jedi-hunting Inquisitors and Darth Vader, occasionally sought both Jedi and Sith holocrons in hopes of acquiring intelligence that would aid in the elimination of their enemies.
Sometime after the Clone Wars concluded, Grakkus the Hutt came into possession of several Jedi holocrons, which he housed on Nar Shaddaa. These were later seized by Darth Vader to further hinder potential Jedi training.
During the early years of the Galactic Empire, on the planet Bogano, Cere Junda stored a message from Obi-Wan Kenobi inside one and used it as an explainer for Greez to Cal for their mission to rebuild the Jedi Order.
By the era of the New Republic Era, when Luke Skywalker was instructing his own Jedi apprentices, he possessed holocrons at his Jedi Temple. Moreover, he employed one to instruct one of his students, Hennix. Dok-Ondar offered both Jedi and Sith holocrons for sale at his Den of Antiquities located in Black Spire Outpost on the Outer Rim world of Batuu.
The initial canon appearance of Holocrons occurred in "Holocron Heist," which served as the opening episode of Season Two of the Star Wars: The Clone Wars animated television program. However, their original development is attributed to Tom Veitch and Cam Kennedy for the Legends comic book series Star Wars: Dark Empire, published by Dark Horse Comics between 1991 and 1992.
Industrial Light & Magic master modelmakers Don Bies and John Goodson fashioned three holocrons (a cubic one, a pyramidal one, and a dodecahedral one) for photographic purposes on page 29 of the Legends reference book titled Star Wars: Attack of the Clones: The Visual Dictionary by Dorling Kindersley, which was released in 2002. All three of these props have since been featured in canon reference books, including Ultimate Star Wars, Star Wars: The Visual Encyclopedia, and Star Wars: The Complete Visual Dictionary, New Edition. These props are currently part of the collection owned by Stephen J. Sansweet at Rancho Obi-Wan situated in Petaluma, CA.
Authentic holocron replicas are available for purchase at Galaxy's Edge, a Star Wars-themed area within Disneyland and Disney's Hollywood Studios.