Definitions, in A Nutshell…
Domain Registrar: A domain registrar offers services that allow you to pick a domain name (e.g. yourwebsite.com). Buying your domain name from a domain registrar is the first step you take when you want to build a website. Your domain name is essentially the face of your websites, while the IP address is the web server your website resides on.
DNS Host: A DNS (Domain Name Server) host is the service that maintains your DNS records and registers (points) it to an IP (Internet Protocol) address (e.g. 123.45.678.90). IP addresses include web servers, mail servers, and other information related to where web browsers need to pull data from. These records are stored as IP settings (for websites), MX settings (for domain mail, e.g [email protected]), and TXT settings for other settings relate to security, permissions, and more.
Web Host: Web hosting is where your website files are stored. Web hosting companies use dedicated web servers that can be accessed via their IP address. Reputable web hosting companies use multiple servers around the world to ensure 100% uptime and speed. Setting your DNS to point to the web host’s IP is what makes the files for your website load into a browser when someone types www.yourwebsite.com into the address bar.
Email Host: Email hosting is where your email files are stored. Email hosting companies use dedicated mail servers that can be accessed via their IP address. Setting your DNS to point to the Email host’s IP is what makes the Email message get to (or come from) firstname.lastname@example.org. This is only used for domain-based email, not generic (free) email accounts (e.g. [email protected]).
The Basics of How This All Works
DNS is the framework of the internet that connects a user who types in a domain name to their desired website. Computers can’t communicate using domain names, so instead, they find each other through the use of IP addresses.
DNS is usually compared to a phonebook. When you want to call someone, you look up their number in your phonebook.
Similarly, when you type a website (e.g. www.brenits.com) into your browser, you are actually performing what is called a query. If your browser doesn’t have the IP address of the webserver where the website files stored in its cache (pronounced like cash) then it will look to the resolving name server which is usually your local ISP (Internet Service Provider).
The resolving name server is like a telephone operator that will have all the local names and numbers. Any websites that were recently queried will have their maps stored in the server’s cache, and you will be connected almost instantly.
If the resolving name server doesn’t already have the mapping, then it will ask the root name servers. These servers are the heart of the Internet and store the maps to all of the IP’s and domain names on the Internet. That’s a lot of information, considering there are 4,294,967,296 possible IPv4 addresses and 340,000,000,000,000,000,000,000,000,000,000,000,000 possible IPv6 addresses.
So instead of holding the complete maps for all the domains, the root name servers will point queries towards the name server that corresponds to the addresses’ Top Level Domain (TLD). The TLD of a domain is the .com or .net part of a domain.
Once you find the right TLD name server, you will be pointed to the authoritative name server for the domain. This server will answer with the domain name that comes in front of the .com you got from the TLD.
Using our telephone operator analogy. If you wanted to make a long-distance phone call from DC to New York City, your local operator wouldn’t be able to directly connect you. Instead, the operator would ask the regional operator on the East Coast (root name server), who would ask the local operator in New York state (TLD), who would ask the even more local operator in New York City (authoritative name server) to connect you.
Who manages all of this?
When you register a domain name you have to go through a DNS registrar (GoDaddy, Network Solutions, domain.com, etc.). These companies often deal directly with the registry operators who control the master list of all domain names. These registries are managed by IANA (International Assigned Numbers Authority) which is a department of ICANN, a nonprofit organization that runs the root zone management in the Domain Name System.
Most people don’t deal with a DNS registrar directly. Instead, they purchase their domain name through a Web Hosting Provider like GoDaddy. These companies do all the work for you and register your domain through the registries on your behalf.
Once you’ve purchased your domain name, you have to tell it which domain name servers will be authoritative (providing directions) for that domain. A DNS hosting provider hosts these servers, which authoritatively respond for your domain.
There are DNS hosting providers that offer domain registration and vice versa (i.e. GoDaddy, Network Solutions, Squarespace). Many of these companies also offer web hosting and Email services. But these services should not be confused. They are distinct and different, and you do not need to use one company for everything. In fact, in some cases, you want to use a different company for each service due to security and speed, among other reasons.