Jedi holocrons were Jedi relics employed for the preservation of knowledge and the teachings of the Jedi Order. These holocrons incorporated a security feature designed to prevent those without Force-sensitivity from gaining access to and unlocking the secrets they contained. The teachings within Jedi holocrons were typically imparted to the individual who opened them through an interactive hologram, appearing as the Jedi Master responsible for recording the information. Sharing the knowledge contained within Jedi holocrons with individuals outside the Jedi Order was generally discouraged, as most holocrons held data concerning the nature and applications of the Force. These holocrons were kept within the Holocron Vault, situated inside the Jedi Archives at the Jedi Temple on Coruscant. Only Jedi serving on the Jedi High Council were permitted access to the Vault.
A elderly female Jedi holds a Jedi holocron
In many cases, holocrons required a memory crystal to be unlocked, for example, the Kyber memory crystal that was entrusted to Bolla Ropal, the Rodian Jedi Master, during the Clone Wars, which held a comprehensive list of all known Force-sensitive younglings. Cad Bane, a bounty hunter in the service of Darth Sidious, the Sith Lord, captured Ropal and seized the Kyber crystal after stealing a holocron from the Jedi Temple. Ropal refused to unlock the data for Bane, but Bane later managed to compel Anakin Skywalker, a Jedi Knight, to open the holocron for him after capturing his Padawan, Ahsoka Tano.
Later during the conflict, Jedi Master Depa Billaba possessed a holocron that she bequeathed to her apprentice, Caleb Dume, following the Conquest of Kaller and shortly before her demise during the Great Jedi Purge after Order 66 was initiated by Darth Sidious. Ezra Bridger, Ahsoka Tano, and he used it until 2 BBY when it was destroyed during a fusion with a Sith holocron.
Grakkus, the Hutt crime lord, amassed a collection of Jedi artifacts after the Great Jedi Purge, which included holocrons stored within his palace on Nar Shaddaa.