Private name servers are generally only used by professional web hosting companies and resellers.
When you set up private name servers as a reseller whois searches will show ns1.yourdomain.com and ns2.yourdomain.com which masks that you are using our services. Your clients can also use ns1.yourdomain.com and ns2.yourdomain.com instead of the default nameservers.
To create new name servers login to your domain name registrar and manage your domain name. If you need assistance setting up A records on this end, please submit a support ticket.