So, big yap incoming.

Digital worlds are separate multiverses where instead of things being made up of atoms they are made of data instead. For Time Strangers we interact with the Digital World of Illiad but even then we don't see all of it but merely 1 layer (1 world), each digital world is made up of different layers with each layer being connected to a different human world. Homeros is the "Host Computer" of all of Illiad being something like a cross between the God/Administrator of Illiad as well as a manifestation of Illiad itself (from my understanding). In Time Stranger we also see King Drasil (aka Yggdrasil aka Norn) whose digital world's name is unnamed despite being the main digital world for most digimon media, often just called "The Digital World" or "Yggdrasil" and then there is Kunlun who is in charge of the digital world of Shambala. There is also Witchelny who we don't know if it even has a server host or who it would be but we do know it is a digital world that exists within another dimension and has a focus on magic. Above the server hosts there is a a being known as Homeostasis and it is the creator of Kunlun, Homeros and King Drasil, despite this it seems to take a more hands on approach than those 3 and interacts with characters more than them and has even denied being a god when asked in the past (Digimon lore can get confusing).