History, Areas, and Lore

Current Time
Earth: 201X // Digital World: New Era Year 100

New Era Years
'Era' is the name by which the invader of the Digital World is known; the Digimon keep time now in 'New Era' years, which began when Era himself invaded. (It's a bit of a gallows-humor joke to them.)
Time in the Digital World passes at a ten-to-one rate when compared to the real world; that is to say, in one year of Real World time, ten years have passed in the Digital World. Ergo, Era attacked the Digital World 100 years ago from an internal perspective, and 10 years ago from a hypothetical Real World observer.

Yggdrasil and the Five Sovereigns
Yggdrasil (in the continuity of Digimon re:GENESIS) is the great 'core' of the Digital World, located at the exact center of the Digital World; a creature, whether of flesh or of data, cannot approach Yggdrasil, unless it has reached the status of, or has the express blessing of, the great Digital God, the Sovereign of the Center, Huanglongmon. It is said among Digimon that to look upon Yggdrasil without the aforementioned would cause instant cessation of existence.
Yggdrasil takes the form of a great, shining-white world tree, encircled by data. It is circled around at its very center by Huanglongmon. Yggdrasil is said to be the link between the Digital World and all other dimensions, and it is through Yggdrasil that the Chosen Children are summoned to the Digital World. The D-GEAR units have cores comprised of Yggdrasil's data, which gives them their power. That said, Yggdrasil itself does not seem to be sentient.
Around Yggdrasil, on a horizontal plane at which Huanglongmon is the center, rest the four other Sovereigns, each perpetually in their cardinal direction-- Ebonwumon to the north, Baihumon to the west, Zhuqiaomon to the south, and Azulongmon to the east. All five of them, were they to be seen by mortal eyes, would appear to be hibernating, but in fact are in constant communication with one another and the outside Digital World.
All actions of Yggdrasil are set in motion by, and only by, the Sovereigns. The Sovereigns are the rulers of the digital world, and Yggdrasil is the means through which they enact their decisions.

Yggdrasil is said to be the link between the worlds, but the extent of this is unclear.

Areas


note: map is not totally to scale

The Digital World is split into a number of main 'Areas', very few of which remaining totally free of Era control. Areas seen in-story are shown and listed above (and will be added to the map as they are seen). Rings on the map indicate the location of a Sovereign.

Areas are connected to one another by means of Proxy Areas, which transform data from one form to another so that it may pass through to the next Area, described by Emily as akin to doing a cut and paste action on a file. Proxy Areas take the forms of areas such as tunnels, caves, sewers, usually adapted to fit where they are located and what Areas they connect.

When moving between Areas, the Proxy Areas are essential because they will sometimes rearrange an individual's data to better fit an area; for instance, any Proxy Area leading into the Great Ocean area will rearrange all comers' data so they may breathe underwater, as more than 95% of the area is, in fact, underwater.

As the Digital World is at least as vast as the Real World, it is yet to be seen how much of it the team will manage to cover.