Name Server

A  Name Server  is something you configure on your domain registrar to point to your web host; it’s part of how someone views your website, from typing your domain name into a browser, which looks up your domain name and finds your registrar, whose name servers point to your web host, which then serves your personal site to the browser.

How to configure
When you login to your domain registrar, find a place to edit or configure your domain.

There you should see a field or option to set: with a text field of entries like: ns1.example.com ns2.example.com ns3.example.com
 * Name Servers

Get the values for those entries from your web host.