Padmé Amidala hides a hologram disc away from Rush Clovis
Hologram discs, which are also referenced as holodiscs, holodisks, or even holotape, functioned as a kind of storage medium. Holograms could be saved onto them.
During the period of conflict known as the Clone Wars, Senator Padmé Amidala embarked on a mission to Cato Neimoidia. While there, she downloaded the precise tactical location of a new Separatist droid foundry financed by the InterGalactic Banking Clan. This information was placed on a hologram disc, thus proving that Senator Rush Clovis, the Banking Clan's representative in the Galactic Senate, was secretly collaborating with the Separatists.
A holodisk was discovered by Ezra Bridger inside his parents' old holotransmitter. Sabine Wren, his friend, cleaned the disc and discovered a holographic image of him with his parents. She then presented it to Bridger as a belated birthday gift.
By the later years of the Galactic Civil War, holodiscs had become the favored method for storing data within the Anoat sector. Furthermore, they could function as a form of currency. The Data Seekers of that sector would exchange secrets that had been recorded onto these discs.
The novel Han Solo at Stars' End, written by Brian Daley in 1979 as the first book in The Han Solo Adventures trilogy (Star Wars Legends), was the first time hologram discs were mentioned. They became part of canon when one was featured in "Senate Spy," which was the fourth episode of the second season of the Star Wars: The Clone Wars animated series.