Unus mundus ("one world") is a concept from Carl Jung that defines a state beyond the known universe where every contradiction in physics can be explained.
The U.M.N. is a part of daily life to many in the Xenosaga universe. It is essentially an interstellar network akin to hyperspace or subspace, enabling faster than light communication and travel. Column Areas
are points in physical space that intersect with the U.M.N. and allow transition into hyperspace for travel.
The U.M.N. Management Agency on Second Miltia is the owner/operator of the Network, and collects fees for its use by other organizations. However the Agency is almost entirely supported by Vector Industries, which also controls the available information and research on the existence and development of the U.M.N. Through this exclusive knowledge, Vector was able to create the only vessel (the E.S. Dinah)
capable of entering hyperspace without interacting with the U.M.N.
Logo and Mascot
The logo of the U.M.N. is an Ouroboros, a serpent eating its own tail. In order to establish mass appeal, Vector also created a mascot, known as "U-kun" or "Bunnie". This mascot is featured prominently on the box art of Xenosaga Freaks, and appears in many in-game displays and the U.M.N. codex.