[Is there always a sequential nature of time-stepping?][1]

OP essentially asks if sequential time stepping for numerically solving a PDE is a necessity or not. OP describes this general issue from a concrete perspective which probably seems like lacking in details. Nevertheless, the question is general at its core and already has a nice answer that presents approaches alternative to sequential time-stepping.

There is no comment that would explain what would the optimal shape of the question with more "details or clarity" be. In my mind, the question is clear enough to anyone capable of answering it. The optimal outcome would IMHO be to open the question and accept the current answer.

**EDIT** to add new bits of information: The question and answer got some upvotes, remains closed. OP seems like a new user with one question and no activity outside of it. The question can be rewritten to whatever suitable form but it seems that there is no consensus on what is the suitable form of the question. (Or even questions in numerical mathematics in general.)

**EDIT 2**
Question remains closed after "The community reviewed whether to reopen this question" since "Original close reason(s) were not resolved." The original reason(s) are "Needs details or clarity" which, according to [help page][2] means that more information is needed. Said help page also suggests: "Edit your post to be more specific about what you're looking for, and be sure to address any concerns that other users brought up in the comments." But there are no concrete comments, not even here, and the question is broad but imho specific enough.

(Sorry for the late edit, I was afk for a while.)

I think that the question if timestepping has to be done sequentially has a value to the site and closing it is counterproductive in the long run. (As long as you include numerical mathematics into "mathematics.") I have no problem improving the current question or asking a similar question. But it seems like a waste of time seeing the current question closed without any actionable explanation.

  [1]: https://math.stackexchange.com/questions/4918429/is-there-always-a-sequential-nature-of-time-stepping
  [2]: https://math.stackexchange.com/help/closed-questions