Addresses (e.g., ns1.webwolfservices.com and ns2.webwolfservices.com), much like your house address, which point your domain to the proper web hosting server so that when someone enters your URL in their brower's address bar, your web page is displayed correctly in their browser. You will use the nameservers sent to you in your Welcome to WebWolf email after signing up for a WebWolf Services hosting account.
The machines which direct domain names to the IPs and servers that make them function. There are 2 ways nameservers are used. Authoritative nameservers keep the records for a given domain name which are the final authority on where it resides. Local resolution nameservers are the machines that look for a domain name when you try to access it through your ISP.
A nameserver is a special Internet address listed on a domain name to tell that domain where to send people looking for your website. When you move hosting companies you normally need to update the nameservers on your domain name.