Before reading this article you can find information here about DNS records. A DNS zone is here we keep our DNS records. In Azure a private DNS zone is where we keep our records for specific domain. To publish a private DNS zone to your virtual network, you specify the list of virtual networks that are allowed to resolve records within the zone. These are called linked virtual networks. When auto-registration is enabled, Azure DNS also updates the zone records whenever a virtual machine is created, changes its IP address, or is deleted.