Azure's central networking point that connects multiple networks, branch offices, and VPN connections. Like a grand central station for network traffic - all routes converge here and get directed to their destinations.
A global corporation uses Virtual WAN Hub to connect 100+ branch offices worldwide to their Azure resources through a single, managed hub.
All provide a hub-and-spoke style connectivity layer to interconnect multiple networks (VPC/VNet), on-prem sites, and routing domains. Azure Virtual WAN Hub is a managed hub inside Azure Virtual WAN that can aggregate VPN/ExpressRoute, connect VNets, and optionally integrate security/NVA services. AWS Transit Gateway is the closest functional match for VPC and on-prem aggregation. GCP Network Connectivity Center provides a hub for hybrid and spoke connectivity (often with Cloud VPN/Interconnect). OCI Cloud Router provides dynamic routing for connectivity (commonly paired with FastConnect/IPSec) but is not a full managed WAN service in the same way as Azure Virtual WAN.