Lets understand some more networking concepts

• Routing: The basic functionality is Router is to forward the packet from one network to another
  
  
• When we create a network with some subnets, each subnet will have router with some rule defined to forward the packets. These rules are referred as Route Tables.
• How the Internet connectivity is working at your home (NAT Gateway)
  

Exercise: I need 4 subnets with 250 devices each, Create a network cidr for subnets and the network

Azure Virtual Network (VNet)

• This is the fundamental building block for your private network in Azure
• We can use VNET to
  • Communicate between Azure Resources:
    • You can deploy VM and several other types of resources to a virtual network (Azure App Service, Azure Kubernetes Services, Azure VMSS)
  • Communicate between each other:
    • You can establish connections between two virtual networks in Azure.
  • Communicate to the internet:
    • All resources in a VNET can communicate outbound to the internet by default.
    • From Internet if you want to connect to some resource in VNET, The resource should have a public ip.
  • Communicate to the On-premises connections:
    • We can communicate on-premises networks using VPN Gateways and Express Route.

References

• Global Infra Map Refer Here
• To Create a VNET, We need to understand About Azure Global Infrastructure
  
• In Azure When We create a VNET, We choose a Region. i.e. scope of network is one Region.