Nameservers define your domain’s current Domain Name System (DNS) provider and most domain name registrars provide free DNS services. Nameservers are a fundamental part of the DNS. They allow using domains instead of IP addresses. It is like contacting your friend by phone: Before calling, you look up his/her telephone number or write it down not to enter the numbers each time.
Heart use the following nameservers:-
Please remember that name server changes take up to 72 hours to come into effect, if you specify your own nameservers please ensure they are configured to provide DNS for this domain name.
Changing your domains name servers to offsite nameservers will prevent features such as web forwarding and web hosting from working.