What is a nameserver?
A Name server is a server that acts like a phonebook of the internet. Its job is to turn a domain name that humans can read (eg: skunkworks.ca) into an IP address that computers can read (eg: 96.53.35.230).
This job is called DNS (Short for Domain Name System) and it is critically important to how the Internet functions.
There are two types of DNS servers that you are using daily as an internet user. Recursive and Authorative.
1. Recursive DNS
If you are a web surfer, your ISP provides you with a pair of IP addresses. Sometimes you are required to enter these IP addresses into your home router and sometimes they are just built-in to the modem or router your ISP provided.
You never need to think about them but, quietly in the background, these IPs are critical to ensuring your Internet service works. They point to what are known as recursive DNS servers. These are often operated by your ISP and are provided free as part of your internet plan. When you type a domain into your browser, or click on a link, your computer queries the IPs of these recursive DNS servers and asks if they know what the IP for a particular domain is.
The problem
Unfortunately, many ISPs under-invest in their DNS infrastructure. If your browser ever stalls and you see Resolving example.com… in the status bar (where example.com is the domain of the site you’re trying to look up) chances are it means your ISP’s DNS is having problems.
Think of recursive DNS like a cache. Since the total universe of domains and their corresponding IPs is large, recursive DNS servers typically don’t store a copy of everything. If a recursive DNS server has had a query for a domain recently, then it can return the corresponding IP from its cache if another request for the same domain comes in later. The length of time a domain is cached by a recursive DNS server is known as the time to live (TTL) and it is specified by the domain’s owner.
The solution
Alternative Recursive DNS services like OpenDNS or Google’s Public DNS can replace your ISP’s recursive DNS and often provide a far superior Internet experience. Skunkworks uses OpenDNS at our office. Many of our staff use Google's Public DNS at home instead of Shaw or Telus' offering.
2. Authoritative DNS
Recursive DNS acts as a cache and returns results it already knows. If a recursive DNS provider gets a request for a domain where the IP isn’t already cached, it retrieves the result from the authoritative DNS server for a particular domain.
The problem
Many registrars like GoDaddy, Register.com, or Network Solutions provide authoritative DNS service for domains you register with them. Unfortunately, much like with ISPs and recursive DNS, authoritative DNS is often underinvested in and servers allocated to it are overloaded.
The solution
CloudFlare has built one of the most state-of-the-art DNS systems in the world. They provide you with a set of authoritative DNS servers like lola.ns.cloudflare.com or ben.ns.cloudflare.com.
Thinking of Cloudflare’s authoritative DNS servers as individuals is actually quite misleading. In actuality multiple servers to respond to any request. What that means is that the set of name servers Cloudflare gives you actually points to a clusters of servers in each of the global data centers they run. What that means is not only is your DNS faster because it is located closer to the recursive DNS server making the request, but even if a single server or even a whole data center is knocked offline there will still be many more name servers standing in reserve to pick up the slack.
There are companies that charge big bucks for this type of DNS service like Cloudflare has built. It rivals in terms of number of data centers and physical servers answering DNS some of the biggest names in the DNS business. And it’s included free with every CloudFlare account.
Summary
So where a Recursive DNS Nameserver is for web surfer's modems or routers, An authoritative DNS Nameserver like CloudFlare is for domain names and websites.