Gateway types
When you create a virtual network gateway, you need to specify several settings. One of the required settings, -GatewayType, specifies whether the gateway is used for ExpressRoute, or VPN traffic.
Vpn - To send encrypted traffic across the public Internet, you use the gateway type 'Vpn'. This type of gateway is also referred to as a VPN gateway. Site-to-Site, Point-to-Site, and VNet-to-VNet connections all use a VPN gateway.
ExpressRoute - To send network traffic on a private connection, you use the gateway type 'ExpressRoute'. This type of gateway is also referred to as an ExpressRoute gateway and is used when configuring ExpressRoute.
Each virtual network can have only one virtual network gateway per gateway type. For example, you can have one virtual network gateway that uses -GatewayType Vpn, and one that uses -GatewayType ExpressRoute.
Gateway SKUs
When you create a virtual network gateway, you need to specify the gateway SKU that you want to use. When you select a higher gateway SKU, more CPUs and network bandwidth are allocated to the gateway, and as a result, the gateway can support higher network throughput to the virtual network.
ExpressRoute virtual network gateways can use the following SKUs: