Domains, DNS and Web Hosting Explained Without the Jargon

When someone types your business's web address into a browser, a surprising amount happens in the moment before your homepage appears. Three separate things make it work: a domain name, the Domain Name System (DNS), and web hosting. They are often bought from different companies, billed separately and managed in different dashboards, which is exactly why they confuse so many business owners.

Understanding how they fit together pays off. It helps you avoid losing your domain to an expired credit card, makes moving to a new website far less stressful, and lets you follow along when a developer says something like "we just need to update your A record."

What a Domain Name Is

Computers on the internet find each other using numeric IP addresses, which are hard for people to remember. A domain name is the human-friendly name, such as example.com, that stands in for those numbers.

Domain names are read from right to left. The last part, such as .com, .org or a country code like .us, is the top-level domain. The part just before it is the name you chose. Anything further to the left, such as the www in www.example.com or shop in shop.example.com, is a subdomain that you control once you hold the domain.

One detail surprises many people: you don't truly buy a domain name. As MDN Web Docs explains, you pay for the right to use it for one or more years, and you get first priority to renew. If the registration lapses and isn't renewed, the name can eventually become available for someone else to register.

Registrars, Registries and ICANN

Three kinds of organizations are involved behind the scenes:

• A registry maintains the master database for a top-level domain, such as everything ending in .com.
• A registrar is the company you actually pay to register your domain. Registrars record your details and pass them to the registry.
• ICANN (the Internet Corporation for Assigned Names and Numbers) is a nonprofit that coordinates the global system. It contracts with registries and runs the accreditation system for registrars. It does not control website content.

For a business, the practical point is ownership of the account. Make sure the domain is registered to your business, that the registrar login belongs to someone in the company rather than only to a former web designer, and that the contact email is one you will check for years to come.

DNS: The Internet's Address Book

MDN describes DNS as an address book for websites. When you type a domain into your browser, DNS is how the browser finds out which IP address to contact.

Your domain's DNS settings live on its nameservers, the servers that hold the official, or authoritative, records for your domain. Those nameservers might belong to your registrar, your web host, or a separate DNS provider. Knowing which company runs your nameservers tells you where to log in when something needs changing.

Each DNS answer comes with a TTL (time to live), a number of seconds that tells other servers how long they may keep a copy before checking again. Because copies are cached all over the internet, changes don't appear everywhere at once. This delay is often called propagation, and it is why a change can work for you but not yet for a customer.

Common DNS Record Types in Plain Terms

Your domain's DNS settings are a list of records. These four are the ones owners meet most often:

• A record: points a name to an IPv4 address, essentially the street address of the server that hosts your site. An AAAA record does the same job for newer IPv6 addresses.
• CNAME record: says one name is an alias for another name, for example pointing www to a hostname supplied by your hosting platform. DNS rules don't allow a CNAME to share a name with other records, so the bare domain usually can't be a CNAME, although many DNS providers offer workarounds.
• MX record: tells the world which mail servers accept email for your domain. Each one has a priority number that sets the order in which servers are tried.
• TXT record: holds a short piece of text. It is widely used to prove domain ownership to outside services and for email authentication standards such as SPF, which lists the servers allowed to send email on your behalf.

Your website and your email are usually separate services that happen to share a domain. Editing the wrong record during a redesign can stop email from arriving, so it's wise to save a copy or screenshot of every record before anyone makes changes.

What Web Hosting Is

Web hosting is renting space on a server that is always switched on and connected to the internet. The host stores your site's files, such as HTML documents, images, stylesheets and scripts, and sends them to visitors on request.

MDN distinguishes two broad setups. A static server sends stored files exactly as they are. A dynamic server adds software and usually a database, assembling pages on the fly before sending them, which is how most content management systems work. Hosting plans range from inexpensive shared hosting, where many sites share one server, to dedicated or cloud servers and managed platforms. Hosted website builders bundle hosting into their subscription.

Because the domain and the hosting are separate, you can usually move your website to a new host without changing your domain. You simply update the DNS records to point to the new server.

How a Page Request Travels

Here is a simplified view of what happens when someone visits your site:

1. A visitor types your domain into the browser and presses Enter.
2. The browser checks whether it already knows the IP address from a recent visit.
3. If not, it asks a DNS resolver, usually run by the visitor's internet provider or a public DNS service, which finds your domain's nameservers and returns the IP address.
4. The browser opens a connection to that server and, for an HTTPS site, sets up an encrypted connection.
5. The browser sends an HTTP request asking for the page.
6. The server responds, typically with a 200 OK status, and sends the page's HTML in small chunks called packets.
7. The browser reads the HTML, requests the images, styles and scripts it needs, and assembles the finished page.

A Quick Checklist for Owners

• Know which registrar holds your domain and who has the login.
• Turn on auto-renew and keep the payment card up to date.
• Know which company runs your nameservers.
• Keep a saved copy of your DNS records.
• Know who hosts your website and how backups are handled.

Key takeaways

• A domain name is a renewable registration, not a one-time purchase, so keep renewals and account access in your business's hands.
• DNS translates your domain into the address of the server that hosts your site, and changes can take time to spread because of caching.
• A, CNAME, MX and TXT records control where your website, email and verifications point.
• Hosting stores and serves your site's files, and it can usually be changed without changing your domain.

Sources

• MDN Web Docs: What is a domain name?
• MDN Web Docs: How the web works
• MDN Web Docs: What is a web server?
• ICANN: What Does ICANN Do?
• IETF RFC 1034: Domain Names, Concepts and Facilities