VNet

VNet, short for Virtual Network, is a software-defined private network that provides isolated networking for cloud resources. It enables resources such as virtual machines, containers, and managed services to communicate securely within a defined address space and to connect to on‑premises networks or the internet under controlled conditions. In Microsoft Azure, VNet is the foundational unit for network topology and resource placement, while other cloud platforms use similar constructs (for example AWS VPC, GCP VPC).

A VNet defines an address space, typically using IPv4 and optionally IPv6, and is subdivided into one or more subnets. Each resource attaches to a subnet through a network interface and receives a private IP from the subnet range. VNets support DNS configuration, routing, and security controls such as network security groups (NSGs) and route tables. Subnets can isolate tiers of an application, and NSGs can enforce traffic restrictions by rules. VNets also integrate with platform monitoring and logging services for visibility and auditing.

Connectivity and integration options enable hybrid and multi-network deployments. VNets can be connected to other VNets through peering, to on‑premises networks via VPN gateways for site‑to‑site connections, or through private links such as dedicated circuits. Access to cloud services can be achieved privately via private endpoints or service endpoints, depending on the platform.

Security and management are handled at the VNet level and through associated resources. Administration relies on cloud IAM, with security features including NSGs, firewalls, and user‑defined routes. Monitoring, diagnostics, and traffic analytics are commonly integrated to maintain visibility and control.

Common use cases include hosting multi‑tier applications across subnets, enabling hybrid cloud connectivity, isolating development or testing environments, and controlling egress and ingress through defined routing policies.