What is a domain?
A domain name is an address that you type into a web browser address bar to get a website. An example of a domain name is www.website.com. A domain name is unique to a website and cannot be shared between different websites, and a custom domain name is one that is specifically for your website.
System Services
This system offers both a web hosting service and an email delivery system. To enjoy these services, you might need to connect your custom domain with the system. After connecting the domain with your system, the system will generate a few DNS records to verify your domain authority. You will have to add these records to your domain service provider like Godaddy, Namecheap, etc.