A nameserver translates domain names into IP addresses. If someone types a domain name in their browser, their computer will ask the nameserver which IP address they should surf to. Something similar also happens when an e-mail is sent. This process uses the DNS protocol which is extensively described here.
Your domain will not be available without working nameservers. As a consequence, a nameserver is very important for the functioning of a domain name and therefore the website. That is why Proxeuse equips its systems with at least two nameservers, which can be used for every customer with a Shared or Reseller hosting package.
A domain name is linked to a nameserver. Because you can make this link yourself, the management of the nameserver is in your hands. You can decide at any time to add or adjust a record.