Virtual Networks in Azure

Network traffic between various Azure resources can be logically isolated and controlled using virtual networks. In the cloud, a private network is represented by a virtual network (VNet), which can be set up to span various Azure regions. Through a site-to-site VPN or Azure ExpressRoute, it enables secure communication with on-premises resources as well as with Azure resources, such as virtual machines, cloud services, and storage accounts.

And the major components of Virtual Networks in Azure includes, but not limited to:

1. Subnets: Subnets are logical groups within a virtual network that specify IP address ranges for various resource categories. Depending on the functional needs of each subnet, resources can be allocated to them, and network security groups can be used to regulate communication between subnets.
2. Network Security Groups (NSGs): NSGs are used to manage network traffic to and from resources deployed inside a Virtual Network, both inbound and outgoing. Administrators can design and enforce network security policies using NSGs, which can be deployed at the subnet or network interface level.
3. Virtual Network Gateway: Using a site-to-site VPN or Azure ExpressRoute, the Virtual Network Gateway enables the establishment of a secure link between an Azure Virtual Network and on-premises resources.
4.  Network Watcher: A network monitoring and diagnostic service in Azure, Network Watcher offers insight into the functionality and health of Virtual Networks. It can be used to keep track of network activity, resolve connectivity problems, and learn more about the topology of the network.
5. Virtual Network Peering: Through the use of a private and secure connection, two virtual networks can be linked together. As a result, resources in various Virtual Networks are able to communicate with one another as though they were on the same network.
6. Azure Firewall: Azure Firewall is a managed, cloud-based network security service that offers resources deployed within a Virtual Network network and application-level protection. It can be used to safeguard resource access, filter network traffic, and enforce network security policies.