What Is a Domain Name and How Does It Work?
A domain name is the human-readable address people type to reach a website or online service — like sedo.com. It works by mapping that readable label to a numeric IP address through the Domain Name System (DNS), so you don't have to memorize strings of numbers. You need a domain name if you want a stable, memorable address for a website, email, or brand. You can get one either by registering a new, unclaimed name through a registrar, or by buying an already-registered name on an aftermarket marketplace such as Sedo.
Domain name vs. URL, website, and hosting
These four terms get used interchangeably, but they describe different things:
| Term | What it is | Example |
|---|---|---|
| Domain name | The registered address label | example.com |
| URL | The full path to a specific page or file | https://www.example.com/pricing |
| Website | The content (pages, images, code) served at an address | The pages you see at that URL |
| Hosting | The server space where the website files live | The service storing those files |
A useful way to think about it: the domain name is the street address, hosting is the building on that land, the website is what's inside the building, and the URL is the directions to a specific room.
The parts of a domain name
Reading a domain from right to left:
- Top-level domain (TLD) — the ending, such as
.com,.org, or a country code like.us. This is the broadest category. - Second-level domain — the part you choose and that makes the name yours, such as
sedoinsedo.com. The combination of second-level name + TLD is what you register. - Subdomain — an optional prefix you control, such as
blog.example.comorshop.example.com. Subdomains don't need separate registration; you create them through your DNS settings.
So in blog.example.com: blog is the subdomain, example is the second-level domain, and .com is the TLD.
How DNS turns a name into an IP address
Computers locate each other by IP addresses, not names. DNS is the system that translates one into the other. When someone types your domain into a browser, roughly this happens:
- The browser asks a DNS resolver to look up the name.
- The resolver queries a hierarchy of name servers until it reaches the authoritative name server for your domain.
- That server returns the IP address (and other records) associated with the name.
- The browser connects to that IP address and requests the page.
The key practical point: your domain and your hosting are linked through DNS records. You point your domain at a server by setting records such as an A record (maps a name to an IPv4 address) or a CNAME record (points one name to another). Changing hosts usually means updating these records, not moving the domain itself.
How domains are registered, owned, and renewed
Domains aren't bought outright in the way physical property is. They're registered for a fixed term — commonly one year at a time — through an accredited registrar.
- Registration gives you the exclusive right to use that name for the term you paid for.
- Ownership is tracked in a registry database, with your contact details (often privacy-protected) on record as the registrant.
- Renewal is required. If you let a domain lapse, it can expire and eventually become available to others. Most registrars offer auto-renew to prevent accidental loss.
- Transfer lets you move a domain between registrars, usually by unlocking it and using an authorization code.
Because renewal is ongoing, the real cost of a domain is the registration or purchase price plus the recurring renewal fee.
Registering a new domain vs. buying a premium or aftermarket domain
There are two distinct paths, and they differ in price, availability, and process:
Registering a new domain
- You search for a name that no one currently holds and register it through a registrar.
- Typically the lowest-cost route, with standard renewal pricing.
- Best when your preferred name is still unclaimed.
Buying a premium or aftermarket domain
- The name is already registered, and the current owner is offering it for sale — often through a marketplace like Sedo, which lists domains for sale and premium domains.
- Pricing is set by the market or the seller and can be far higher than a standard registration, reflecting the name's perceived value.
- Best when the exact name you want is taken and matters enough to your brand to pay for it.
Sedo operates as a marketplace for buying, selling, and parking domains, so both new registrations and aftermarket purchases can fit into the same workflow depending on what you need.
What this means for your next step
If you just need any available name, start with a registrar search and register it, then point its DNS records at your hosting. If the name you want is already taken and central to your plans, look at aftermarket listings and expect market-based pricing. Either way, plan for renewal from the start — a domain is a recurring commitment, not a one-time purchase.