Cloud (or bulk) domains is an internal feature of ClouDNS that allows you to manage the records of your multiple domains. If you have many domains with the same records, you can add them to the cloud of yourdomain.com. After that, if you make any changes to the records of yourdomain.com, all the changes of it will be reflected to your cloud domains. For example: If you have many domains, pointed to the same IP address, you can use Cloud domains.
To use this feature, you need first to create a Master DNS Zone. When your zone is created, you will be able to add all of your domains in Cloud domains and they will have the same records as your master domain. When you change any of the records in your master zone, the changes will reflect to all of the domains in your Cloud.
If you don't know how to create Master DNS zone, you can check it here.
How to use it?
Go to the Control Panel of your Master DNS Zone and click on the "Cloud Domains" button, located between "Records Templates" and "Mail Forwards" buttons.
Enter the domain names you want in the white box. You must add the domain names one per row.
Click on “Add cloud domains”.
You are ready! The domains are added to your Cloud and they have the same records as these in your Master DNS Zone.
How to add Cloud Domains in ClouDNS - Step by Step: