Azure Virtual Network (VNet) is the equivalent of a virtual private cloud (VPC) in Microsoft Azure. It is a fundamental networking construct that allows you to create isolated and secure network environments within the Azure cloud. Azure VNets enable you to host and connect various Azure resources, such as virtual machines (VMs), web apps, databases, and more, in a private, controlled network space.

Here are some key aspects and features of Azure Virtual Networks (VNets):

1. Isolation: VNets provide network isolation, allowing you to create multiple isolated environments within Azure. Each VNet operates independently, and resources within one VNet cannot directly communicate with resources in another VNet unless you establish connectivity between them.

2. Subnetting: You can divide a VNet into multiple subnets, each with its IP address range. Subnetting helps organize and segment resources within a VNet and allows you to apply different network security and routing rules to each subnet.

3. Connectivity Options: Azure VNets can be connected to each other or to on-premises networks through various connectivity options, including Virtual Network Peering, Site-to-Site VPN, and ExpressRoute. This enables hybrid cloud scenarios and facilitates secure communication between Azure and on-premises environments.

4. Security Groups and Network Security Groups (NSGs): VNets allow you to apply security rules using Network Security Groups (NSGs) to control inbound and outbound traffic to and from resources within the VNet. You can also use Azure Firewall for advanced network security and threat protection.

5. Private IP Addressing: Resources within a VNet can have private IP addresses, and public IP addresses can be assigned to specific resources, such as load balancers or gateway devices, to enable public-facing access.

6. DNS and Name Resolution: Azure VNets provide built-in Domain Name System (DNS) services for name resolution within the VNet. You can also integrate Azure DNS or use custom DNS servers for more advanced configurations.

7. Routing: You have control over routing within the VNet, including user-defined routes (UDRs) to customize traffic routing for specific scenarios.

8. Service Endpoints: Azure VNets support service endpoints, which allow resources within a VNet to securely access Azure services, such as Azure Storage and Azure SQL Database, without internet egress.

9. ExpressRoute Gateway and VPN Gateway: Azure VNets can be associated with ExpressRoute Gateway or VPN Gateway for dedicated and secure connectivity to on-premises networks or remote offices.

10. Resource Groups: VNets can be organized into resource groups, which helps manage and group related resources together for better organization and management.

11. Availability Zones and Availability Sets: You can deploy resources within VNets across Azure Availability Zones or use Availability Sets to ensure high availability and fault tolerance.