I asked this questiion yesterday: Does the shape of the Universe refer to the curvature of spacetime in 5-dimensional space?
While I now understand and got good answers, my question was closed as duplicate. However, in my opinion, the linked questions are questions around the same topic, but a different question:
In the following, I try to briefly sum up the core of the linked questions.
Question 1: Is your 3-dimensional universe part of the surface of a 4-dimensional sphere [like in the ant-sphere analogy] that we cannot perceive or access?
Question 2: The correctness of the bend-sheet-analogy for GTR
Question 3: Could the universe be bend over a forth dimension to form a 4-dimensional shphere?
The essence of my question (linked above) was: When we refer to the shape of the universe (being flat e.g.), do we mean the same curvature as in GTR (as in being warped over a forth dimension)?
The answers (again - thanks to Shashaank and bapowell!) clarified that I was about half-correct: It is the same curvature as in GTR, but as this is intrinsic curvature, a forth dimension is not necessary (however not wrong).
I see that the linked questions are somewhat similar (especially the third), but in my opinion, it is still a different question (e.g. all the linked questions either referred to GTR or the universe's shape but did not ask whether these refer to the same principles).
So why was my question closed?
(Note: I do not ask this question because I am angry about my question being closed (as I said before, I got great answers, so I'm fine) or to hate against those that closed it - I just want to know the reasons so that I can ask better questions in future.