In a GEO cluster, do we need 3 independent Data Centers? On MON per datacenter?

Due to quorum we need minimum 3 Monitors. Does it means in GEO cluster we need 3 independent Data Centers?? One Mon per datacenter?

From a very technical perspective, yes, you would need 3 datacenters. But it’s very common (and perhaps I could say that it’s recommended) to have only 2 datacenters, with a “faux” datacenter hosting the third monitor. That third monitor could be anywhere, whether in datacenter A or datacenter B, or in an isolated closet all by itself.