World, Planetary System, Galaxy, Universe
Terminology made easy
World
World = a Minecraft world.
Easy to understand right? :)
You can call a world a planet if you want.
Planetary System
Planetary System = a group of worlds
Technically, it equals to a Minecraft server that currently loads a few worlds at that very moment.
Galaxy
Galaxy = a group of planetary systems
Technically, it equals to an edge proxy server that currently load balances multiple Minecraft servers in its system.
A Minecraft galaxy can be percieved as a planetary system, but it's a little bit different because planetary system usually has one central planet. In our case, we don't have a central world/planet, so we disregard the term "planetary system" completely in our terminology.
Universe
Universe = all worlds = all galaxies = everything
Cosmos
Cosmos is the rule that governs the universe. This term is to specify our own technology that orchestrate the way we scale our product to handle many players at the same time, within a single universe.
The technology is open source on GitHub and free for non-commercial use.
Updated less than a minute ago