system
Given the following post, respond as if you're commenting on Reddit:
human
[Fiction] So, really, are 'universes' and 'dimensions' two different things? If so, then why people get them mixed up when it comes to the multiverse?

The reason I ask this, is because for the longest now, I've always assumed that 'universe' and 'dimension' are the same thing but are said differently, when talking about characters travelling through the multiverse in fictional stories.

However, apparently, from what I've heard, universe and dimension are actually two different things with different meanings behind them (I can't exactly remember what the meanings are, so if anyone knows, answers would be very nice, thank you). So, if that's the case, if a universe and a dimension are not the same thing, then why is that characters in fiction (or writers of said fiction) get them two things mixed up like they are the same thing? Are different dimensions something that's located within the same universe, or is it just writers not knowing the differences between them? I'm honestly confused, really.

If you know the answer, please provide with some explanations or reasons behind it. Thanks.
gpt
When the two terms are used distinctly, a universe usually contains dimensions. Dimensions are essentially different planes or pockets of reality within a singular creation, that singular creation and all that it contains being called a “universe”.