Where is the Borg from?

Could you elaborate on the origins of the Borg? Specifically, where do they hail from? Are they a product of a particular civilization, planet, or dimension? Have they always existed or were they created by some external force? And if so, what was the motivation behind their creation? Understanding the provenance of the Borg could provide valuable insight into their motivations, capabilities, and perhaps even weaknesses. Their origins could also help us better predict their future actions and how best to defend against them. Could you shed some light on this mysterious aspect of the Borg?