VPC

A Virtual Private Cloud (VPC) is a logically isolated network section inside a public cloud, where the customer defines subnets, route tables, and firewall rules. Resources inside a VPC get private addresses and communicate over the provider's network without traversing the public internet by default.

VPCs are the main tool for segmenting production environments: a common layout separates public-facing load balancers, application tiers, and databases into distinct subnets, with security groups or network ACLs controlling traffic between them. Peering and transit gateways connect VPCs to each other or to on-premises networks.

When comparing providers, look beyond the existence of VPCs to the details: whether private addresses are free, whether cross-zone traffic inside a VPC is charged, and how straightforward it is to peer VPCs across regions. These details shape both security posture and network cost.