The DISCs are similar in appearance to compact discs but have the word "DISC" engraved on them in capital letters. A Stand can be seen inside the Stand DISCs while memories can be glanced at in Memory DISCs, although a full examination requires the insertion of the DISC.
Despite their appearance, the DISCs feel rubbery and elastic, instead of plastic, making them impervious to physical damage. The DISCs are perennial, existing even long after Whitesnake ceases to exist, and are indestructible unless inserted into a dying person, causing the inserted DISC to slowly crumble.
Unlike Stands, an ordinary person can see the DISCs.
These DISCs contain the Stand of the person in question. A person with their Stand DISC taken from them will collapse into a near-death state. Stand DISCs can be inserted into compatible users, even enabling some such as Emporio to temporarily bypass the one-Stand rule. A Stand DISC may reject an incompatible host (such as Star Platinum's did Jolyne), so Pucci will typically seek out people whose personalities align with the Stand's abilities, such as the suicidal Thunder McQueen being granted Highway to Hell.
These DISCs contain the memories of the person in question. Depending on Pucci's wishes, a Memory DISC can either store the entirety of someone's memory or individual memories. These DISCs are mainly used to store information and abilities for later use and can be consulted or used by putting the disc inside someone's head.
Pucci is able to create other types of DISCs. By inserting DISCs, Pucci can command people to follow his bidding. For instance, he can brainwash a guard into thinking he's been ordered to kill Jolyne Cujoh without him dwelling much on why or how he's found himself in her proximity. The orders can be quite extraordinary and even physically impossible. For instance, Pucci has been able to command a frog to explode at a preset distance from him. Some DISCs containing a person's sense, like sight, can be extracted.
This DISC was critical for Enrico Pucci's plans, as it contained the exhaustive memories of Jotaro Kujo, most notably his memories of DIO's Diary. Although he successfully learns of DIO's plan, the DISC is reclaimed by Jolyne after their confrontation. It is eventually given to a Speedwagon Foundation agent before the group heads to Cape Canaveral.
Pucci tossed this DISC into the sea, where a colony of plankton assimilated it to become the guardian for Pucci's reserve of Stand DISCs. The colony of plankton, dubbed Foo Fighters, would later become a core ally of Jolyne Cujoh.
A Stand DISC containing Survivor. Pucci extracted the Stand from an unnamed mountain lodge owner for safekeeping after hearing the story about it from DIO, believing it would be useful someday. He'd later endow Guccio with the Stand.
During a meeting between DIO and Pucci, DIO grabs Pucci's arm and asks him if he will betray him someday. DIO dares Pucci to steal The World from him as a DISC, but Pucci refuses, even with his hand right in DIO's forehead.
Pucci kept this DISC close to him as he extracted the memories of his brother, Wes Bluemarine, to seal off the dangerous ability Heavy Weather. The DISC is stolen from Pucci and returned to Weather Report by Donatello Versus.
Pucci extracted his own ability to see, in the form of two DISCs, to become immune to Heavy Weather's sight-based transformation ability. Notably, each one is much smaller than any other DISC, likely due to containing less information.
When he died, Weather Report used Pucci to extract his own Stand as a last gift to his companions. It proved critical in Pucci's demise when Emporio used it to gain the Stand Weather Report's abilities.
The information below derives from a source which was not written by Araki. As such, it may not be considered canon.
At some point, during her time in prison, Fujiko Fujiyama was given a Stand DISC that granted her the ability Bad Romance. However, later on, Enrico Pucci becomes angered at Fujiko for drawing religious art of Jolyne, and decides to take away her ability.
The Stand DISCs appear in All-Star Battle as part of one of Pucci's skills and his HHA. During those special moves, Whitesnake steals a DISC from the opponent, disabling their special and Style-related abilities until Pucci takes damage. The characters who don't have Stands are not able to use their respective abilities, such as Jonathan's Ripple or Johnny's Slow Dancer.