Box 1: Global Reach -
ExpressRoute Global Reach is the service where if you have two datacenters, which are located at different geo-locations and both are connected to Microsoft
Azure via Express Route then these two datacenters can also connect to each other securely via Microsoft's backbone.
Incorrect:
FastPath is designed to improve the data path performance between your on-premises network and your virtual network. When enabled, FastPath sends network traffic directly to virtual machines in the virtual network, bypassing the gateway.
Box 2: Private -
With ExpressRoute Global Reach, you can link ExpressRoute circuits together to make a private network between your on-premises networks.
Reference:
https://docs.microsoft.com/en-us/azure/expressroute/expressroute-global-reach
