Reference:
https://docs.microsoft.com/en-us/azure/virtual-network/tutorial-connect-virtual-networks-portal You can connect virtual networks to each other with virtual network peering. These virtual networks can be in the same region or different regions (also known as Global VNet peering). Once virtual networks are peered, resources in both virtual networks are able to communicate with each other, with the same latency and bandwidth as if the resources were in the same virtual network.
Global VNet Peering is now generally available in all Azure public regions, excluding the China, Germany, and Azure Government regions.
The address space is the most critical configuration for a VNet in Azure. This is the IP range for the entire network that will be divided into subnets. The address space can almost be any IP range that you wish (public or private). You can add multiple address spaces to a VNet. To ensure this VNet can be connected to other networks, the address space should never overlap with any other networks in your environment. If a VNet has an address space that overlaps with another Azure VNet or on-premises network, the networks cannot be connected, as the routing of traffic will not work properly.
https://docs.microsoft.com/en-us/azure/virtual-network/tutorial-connect-virtual-networks-portal
https://azure.microsoft.com/en-in/updates/general-availability-global-vnet-peering/#:~:text=Global%20VNet%20Peering%20is%20now,transit%20over%20the%20public%20internet.
https://www.microsoftpressstore.com/articles/article.aspx?p=2873369