What is Azure Virtual Network (VNet)?

An Azure Virtual Network (VNet) is the fundamental building block for private networking in Azure. It enables Azure resources like VMs to securely communicate with each other, the internet, and on-premises networks. Key concepts: Subnets: divide the VNet address space into smaller ranges; resources deploy into subnets. Network Security Groups (NSG): firewalls that control inbound and outbound traffic with allow/deny rules. VNet Peering: connect two VNets for low-latency private communication. VPN Gateway: encrypted connection to on-premises network. ExpressRoute: private, dedicated connection bypassing the public internet. All traffic within a VNet is private and encrypted by default — it never leaves the Microsoft network.