Global VNet to VNet peering is when you connect different virtual networks (VNet) across Azure regions. Once the connectivity is established between the virtual networks, traffic is then privately routed through the Microsoft backbone infrastructure providing a low-latency, high-bandwidth connection between your resources meaning no public internet, gateways or encryption is required in the communication between the virtual networks.
This guide shows you how to peer a VNet in the UK South region with a VNet in East US.