Universe

Differences between Universes and Dimensions (according to nexsecure + AshraldRails)
A universe is the world: for example, a tv show has it's own universe and the universe is different than another tv show.

A dimension however: is just a different 'version' of the universe, so there can be a TVshow but in a different dimension it's that exact TV show except every character is a banana, or a dimension where that TV show is cannon in the TV show world.

Nexsecure Dimension is called nexsecure dimension because everything is happening in that one dimension, apart from a few things like the psycho-god who is only in a few dimensions of Nexsecure. Nexsecure Universe is the world or Nexsecure for short, Nexsecure Dimension is the dimension name of where everything happens: Everything that happened in nexsecure dimension is cannon, any other dimension of nexsecure doesn't necessarily have to be cannon.