Definition
Peering, often referred to as VPC peering, establishes a private network connection between two virtual private clouds (VPCs) within the same or different cloud providers. This connection allows resources in each VPC to communicate with each other as if they were on the same network, using private IP addresses. It functions by creating a direct, one-to-one relationship between the VPCs, enabling secure and low-latency traffic flow without requiring gateways or VPNs. Peering is crucial for enabling seamless data sharing and application integration across disparate cloud environments, enhancing operational efficiency. For instance, a company might peer its development VPC with its production VPC to allow secure access for testing without exposing production systems to the public internet. Unlike VPNs, peering does not encrypt traffic by default and is limited to connecting only two VPCs at a time, not transitive connections. Understanding peering is essential for cloud architecture and security domains tested on certifications like AWS Certified Solutions Architect Associate and CCSP.