Where is the difference between discussion, documentation, knowledge base and help system?

I'd like to move the whole Dispute (a documentation) to another place. Individual postings can be moved by the Parent field, but not the dispute itself as it has no Parent field. How can I move it?

I have downloaded a dispute as OpenXML, made some corrections and uploaded it to another dispute. But all changes are ignored. Is it possible to edit it before uploading?