Like a lot of anime, Digimon comes with its own set of terms and concepts which help define the action. This article will collect those terms and try to define them, so I don’t have do so in the individual reviews. I’ll update this article as new terms need to be defined, but this should be a good start.
The Digital World: A world parallel to ours consisting of digital information which manifests as a landscape, inhabited by strange beings called Digimon. The exact nature of of the Digital World is often unknown, or is explained by the story as the plot develops.
Digimon: The inhabitants of the Digital World, Digimon take a wide variety of forms. They are as likely to look like masked humanoids as dinosaurs. Despite that, they are organized into three types: Vaccine, Data, and Virus. Each is supposed to be strong against one of the others, but that pretty much never matters.
Digi-Destined/Chosen Children: The protagonists of Digimon Adventure, these are human children who were transported to the Digital World. They are prophesied to save both worlds, though they don’t know that for a long time.
Partner Digimon: The Digimon bonded to a given Digi-Destined. I’m not actually sure this is an in-story concept, but it describes a dynamic which is definitely present.
Digivolution/Evolution: Digimon are able to shift between forms, thanks to a process called Digivolution. Unless you are in Japan, that is, where it’s just called Evolution. Digivolution always refers to the process of moving into stronger forms, though. Each form is tied to a particular tier, however, which I’ve listed below!
Digi-Egg: When a Digimon dies, its data compresses into an egg, which is called a “Digi-Egg” because this franchise has a very predictable naming scheme. Eventually, the egg will hatch, reviving the deceased Digimon in its Fresh form.
Fresh/Baby I: This is an infant Digimon. It usually resembles a bouncing head. You barely ever see this, because it can’t really do anything.
In-Training/Baby II: This is a somewhat less infant-like Digimon, probably closer to a toddler! At this stage, Digimon gain very rudimentary attacks, which are basically useless. This is also a rarely seen form, almost always representing a tough defeat, or at least a difficult battle.
Rookie/Child: The show’s “default” form for Digimon, this is what they basically walk around as. Occasionally the show will have characters fight like this, but it’s only serious in early episodes.
Champion/Adult: The first digivolved form. I’m not really sure there’s much more to say about these guys, except that they are both important and yet quickly discarded as more powerful forms appear.
Ultimate/Perfect: The second digivolved form. These are truly powerful, and usually comes about as the result of a major moment of character development.
Mega/Ultimate: The third digivolved form. These are among the strongest characters in the show.