The DigiDestined (選ばれし子供 Erabareshi Kodomo?, lit. "Chosen Child") are the main heroes in the Digimon media franchise. They are referred to as "DigiEscolhidos" (Por: DigiChosen) in Brazilian materials. It is used in several Digimon anime series, to refer to special people who have Digimon as partners and are chosen by fate to save the Digital World.
DigiDestined are children selected by benevolent beings to protect the Digital World (and sometimes Earth) from evil forces. The Digital World is a plane on which Digimon, anthropomorphic creatures that originated from data produced by Earth's communication networks, live. The Digital World is volatile and is vulnerable to attack, and the Digimon that live there often find that they cannot defend their world on their own. Therefore, human children are recruited to defeat their enemies.
In Digimon Adventure and Digimon Adventure 02, a DigiDestined is defined by the possession of a Digivice and a link to a Digimon partner. When a Digimon is partnered to a DigiDestined, that child becomes its sole source of Digivolution. Digimon become stronger through Digivolution; this is usually a difficult process to achieve, akin to aging, but a DigiDestined's Digivice and inherent strength amplifies a Digimon's power to the point where it can digivolve more easily, especially if the DigiDestined is in danger.
Digimon Adventure / Digimon Adventure 02
In Digimon Adventure, the DigiDestined are chosen by unseen digital beings who wish to help the Digital World. There is no information on who chooses the DigiDestined of Adventure 02, though it is likely that it is the Harmonious Ones. Most DigiDestined become one by seeing or interacting with Digimon in the Real World, and it is the discovery of this point that helps drive the Adventure DigiDestined's search for their missing eighth member.
Although it has been stated that the DigiDestined from Adventure are chosen because of an earlier battle between Greymon and Parrotmon, the second set of DigiDestined are chosen because of various things that the original group did. Yolei Inoue becomes one because she witnessed the battle with Diaboromon on the internet, Cody Hida is chosen because he was in the plane that Garudamon and MegaKabuterimon saved from crashing when the sky opened, and Davis Motomiya was part of the group of people who were being held inside the convention center when Myotismon was searching for the eighth DigiDestined.
The twelve main DigiDestined in Adventure and Adventure 02 all come from Japan. The first inkling that they are not alone comes when they meet Michael, an American DigiDestined Mimi Tachikawa meets, and who gained his Digivice after seeing a Gorillamon. Late in the series, they discover that there are DigiDestined in many other parts of the world, and they need all the help when Digimon begin to invade the Real World. Unlike the Japanese DigiDestined, some of the international DigiDestined teams have multiple children paired with the same species of Digimon. Not all of the international DigiDestined are named, and not all are shown, but all are equipped with the basic Adventure Digivice, and it takes all of their help to defeat MaloMyotismon.
In Digimon Adventure, it is eventually revealed that another group of children were called upon to be DigiDestined even before the main characters were chosen, despite Koromon initially claiming that the heroes of Adventure were the first humans in the Digital World. These DigiDestined were the first to defeat and seal away a "great evil". The scene that mentions them features silhouettes of Tai, Matt, Sora, Izzy, and T.K. and their Digimon; this was likely done to avoid the cost of new designs, and is not meant to actually depict that group.
Adventure 02 DigiDestined