Configuring a VNet-to-VNet connection is a simple way to connect VNets. Connecting a virtual network to another virtual network is similar to creating a S2S IPSec connection to an on-premises environment. Both the connection types use the Azure VPN gateway. The VPN gateway provides a secure tunnel IPsec/IKE and they communicate in the same way. The difference is in the way the local network gateway is configured.
When you create a VNet-to-VNet connection, the local network gateway address space is automatically created and populated. If you update the address space for one VNet, the other VNet automatically routes to the updated address space. This makes it faster and easier to create a VNet-to-VNet connection than a S2S connection.
To create a VNet-to-VNet connection from the Azure portal, you can refer to the following tutorial: https://docs.microsoft.com/en-us...