I'd like to know the meaning of a question being closed. I am under the impression that the OP is not allowed to revise the question anymore. Is there anything more than that ?
That is false. The OP may revise a closed question as many times as they would like. If they feel that after editing it, the question is now appropriate, the OP can flag their own question with a comment to the moderators to ask them to reopen the question. Some more information about closed questions is here.