The Azure Site-to-Site VPN gateway connection is a similar connection type to Azure VNet-to-VNet, only that this time it is not a gateway subnet that is the goal of the connection setup, but it is a local VPN gateway that gets into your on-premises network.
In the Azure Site-to-Site connection, an IPsec/IKE tunnel is also provided as a secure line between the two gateways. For this connection to be established, the local VPN gateway must have a public IP.
A note of caution: Data traffic performance is unpredictable, as traffic flows over the internet.
In the documentation for Azure networking, you can also find the term, Azure Site-to-Multi Site. This is a variant of the Azure Site-to-Site connection type and uses the VNet VPN gateway to simultaneously serve several local VPN devices.
The number of possible IPsec/IKE tunnels, and thus the connected elements, that can be attached to a VPN gateway is dependent on the selected service level maximum of 30 pieces.
If you are planning an Azure Site-to-Multi Site scenario, you must configure your VNet VPN gateway as RouteBased.
If you are planning an Azure Site-to-Multi Site scenario, you must configure your VNet VPN gateway as RouteBased.