Azure Virtual WAN is a networking service that brings many networking, security, and routing functionalities together to provide a single operational interface.
The Virtual WAN architecture is a hub and spoke architecture with scale and performance built in for branches (VPN/SD-WAN devices), users (Azure VPN/OpenVPN/IKEv2 clients), ExpressRoute circuits, and virtual networks.
Azure regions serve as hubs that you can choose to connect to. All hubs are connected in full mesh in a Standard Virtual WAN making it easy for the user to use the Microsoft backbone for any-to-any (any spoke) connectivity.

Virtual WAN offers the following advantages:
Integrated connectivity solutions in hub and spoke: Automate site-to-site configuration and connectivity between on-premises sites and an Azure hub.
Automated spoke setup and configuration: Connect your virtual networks and workloads to the Azure hub seamlessly.
Intuitive troubleshooting: You can see the end-to-end flow within Azure, and then use this information to take required actions.
Reference:
https://docs.microsoft.com/en-us/azure/virtual-wan/virtual-wan-about