Emulation of Physical Network Infrastructure in the cloud
Allows to connect Azure services together
Can connect cloud and on-premises services together as well
Provides isolation, monitoring, segmentation, communication, filtering between services in the cloud

  • VNets can be further broken down into subnets
  • Allows to group similar resources together
  • Allows for effective address allocation
  • Supports Network Filtering via Network Security Groups (NSG) or Application Security Groups (ASG)

NOTE

  • Subnets cannot be nested
  • By default there is no security boundary around subnets (Services in different subnets in same VNet can communicate with each other)
  • Virtual Networks can only span a single region

Virtual Networks can be connected to each other using:

  • VNet Peering
  • VPN Gateway

Virtual Networks and Virtual Machines in Azure | Microsoft Learn