If I have two same scripts for same effect, one server script using module script, the other one server script don’t use module script just write everything on the server script. Is it the same or if it’s not, which one use more amount of memory or time processing?
I don’t know if this is the right category, but if it’s not you can flag it and tell me in what category should i post about this. Thank you so much.
There is no reason to use a module script if you won’t use it in multiple scripts, because it creates a messy and littered environment. If I understand your scenario correctly I would recommend just using one. Hope this helps! 
Realistically they are going to be the same. Any difference between them in normal use would be negligible. Just use whichever one you think is best for whatever you are doing with it.
Thanks for both your answer, honestly is just a curiousity question , that’s why I said I don’t know if this is the right category. But is it possible to know amount of memory used by server for specific script?
Yep we have debug tools now.