For me, there is no difference.
Student or Learner
Could you, please, explain the difference between ' a top-level meeting' and 'a summit'? Is there a rule when to use one instead the other one?
Thank you very much in advance
I think it depends on the context- if it is a serious meeting of senior politicians on a desperately serious issue, I would be more likely to call it a summit.
It could, but I wouldn't use top-level meeting for what I described.