Google Cloud’s virtual private network. It is a global resource with regional subnets that can be expanded without disrupting VMs. It can be auto mode (one subnet per region) or custom mode, the recommended choice for production.
On the ACE the key point is that the VPC is global and the subnet regional (in AWS the VPC is regional). Every VPC has implied rules that deny ingress and allow egress; the default network also includes rules for SSH, RDP, and ICMP.
Google Cloud VPC is a concept that can show up on the exam. Check the full guide to see it in context.