Well it's more like... where exactly do the Shards exist in XIV's universe? Are they like Drakengard's Earth and NieR Earth where they exist in parallel universes? does NieR Earth exist in the same parallel universe the First exists on? or did 2B and 9S upload their data into the Seed (or whatever) before it appeared on the First? and does that mean there's also a Seed on the Source and other Shards?

I don't really remember all the details on where Shards exist, even if it was explained already.