Sometimes you may need to have several VPCs for different environments, and it may be necessary to connect these VPCs to each other.
VPC Peering allows you to connect 1 VPC to another via a direct network route using private IP addresses. These instances behave as if they were on the same private network. You can also peer VPCs with other AWS accounts, and across regions. Peering is in a hub-and-spoke configuration, and there's no transitive peering (i.e. peering A to C through B).
It's also possible to open your services in a VPC to another VPC by simply allowing access through the internet. [[20220131042104-aws-vpc-privatelink]]
Remember to check for overlapping CIDR ranges