What is a domain?Structure, TLD, DNS and registry explained simply

Published on October 20, 2026

The short answer

A domain is a human-readable name for a technical address on the internet. Instead of 185.119.117.42, you type mainhoster.de. The translation is done by the Domain Name System (DNS) - the phone book of the internet.

So a domain is not storage space and not a website. It is only the name. Where the content lives is only decided by the DNS record you set for the domain - it can point to web hosting, a VPS or a game server.

How a domain is structured

Domains are read from right to left. Using the example shop.yourcompany.com:

What you can register is always the combination of second-level domain and TLD - so yourcompany.com. Everything in front of it is a subdomain, which you create yourself, free of charge and as often as you like. How to find a good name for the second-level domain is shown in Find the right domain name.

Which kinds of top-level domains there are

• ccTLD (country code TLD): country extensions such as .de, .at, .ch, .eu. They signal target market and origin - for a German audience, the obvious choice.
• gTLD (generic TLD): the classic generic extensions .com, .net, .org, .info, .biz. Understood internationally, no geographic statement.
• new gTLD: since 2013, hundreds of new extensions such as .shop, .dev or .berlin. They are descriptive but less widespread - when in doubt, users type a familiar extension after them.

Which extension suits you is covered in the guide .de or .com.

What happens technically when a domain is called up

When you enter a domain in the browser, several steps run in fractions of a second:

1. Your provider's resolver checks whether it has already cached the answer.
2. If not, it asks a root nameserver which server is responsible for .de or .com.
3. The TLD nameserver names the authoritative nameservers stored for your domain.
4. These deliver the actual record - for example the A record with the server's IPv4 address.

Every answer carries a TTL (time to live) in seconds. Until it expires, resolvers deliver the cached answer. That is exactly why DNS changes do not take effect immediately. At MainHoster.de, 4 redundant nameservers per domain are included free of charge. The individual record types are explained in DNS records explained.

Registry, registrar and registrant

Three roles that come up in every domain discussion:

• Registry: operates a top-level domain and keeps the central database. For .de, that is DENIC eG in Frankfurt; for .com, Verisign.
• Registrar: the provider through which you register - technically connected to the registry, usually via the EPP protocol. MainHoster.de acts in this role for you.
• Registrant: the domain owner. That is you - legal and economic owner of the domain, regardless of which registrar it runs through.

That is why switching providers is possible at any time: in a domain transfer, only the registrar changes, not the owner.

Rent or buy?

A domain is not bought, but registered for a term - one year is usual. As long as you renew, you keep the right of use permanently; nobody can take it away from you. If it expires, it becomes free again after a grace period.

At MainHoster.de, this runs prepaid: you pay from your balance, there is no contract and no reminders of unpaid invoices. You trigger the renewal yourself in the web interface; we remind you by email in good time beforehand. If you prefer, you can switch on the optional automatic renewal via PayPal - more in Domain without a contract.

Domain, URL, hosting - the difference

• Domain: the name, for example yourcompany.com.
• URL: the complete address including protocol and path, for example https://yourcompany.com/contact.
• Hosting: the storage space where the files are located - with us, web hosting or a VPS.
• DNS: the connection between the two. Without a matching record, the domain points into nothing.

You can also register a domain without hosting - for example to secure a name, set up a redirect or only run email through it.

Frequently asked questions