What is a domain name?

A domain name is a human-readable name in the DNS hierarchy, such as example.org. It can be used for websites, email and other services, but buying a domain does not automatically create any of them. The name is registered under a top-level domain according to that registry’s rules and then configured through DNS.

How domain names are organised

Read a name from right to left: in www.example.org, org is the top-level domain, example is registered beneath it, and www is a subdomain configured by the domain holder. The dot at the far right represents the DNS root, although browsers usually omit it. A subdomain can point somewhere different from the main name or serve an entirely different purpose.

DNS delegation connects the registered name to authoritative name servers. Those servers publish records such as A and AAAA for addresses, MX for mail and TXT for verification. A domain can exist without address records, and a website can fail even when its DNS is correct. Registration, DNS hosting and web hosting may come from separate providers.

Registration and control

A registrant obtains the right to use a name for a period under the applicable registry and registrar terms. It is not permanent ownership of a word. Keep access to the registrar account, accurate contact information and a reliable renewal method. Missing a renewal can interrupt services or eventually allow someone else to register the name, depending on the registry lifecycle.

A transfer moves the registration to another registrar; changing name servers moves DNS operation; changing an A record redirects a host to another address. These operations are often confused. Before changing providers, export zone data and confirm that mail and verification records will remain available. A domain lock and multifactor authentication can help protect against unauthorised changes.

Choosing a good name

Prefer a memorable spelling that is easy to dictate and unlikely to be confused with another organisation. Check the intended top-level domain’s registration rules, price for later renewals, and any trademark concerns. Internationalised domain names support non-ASCII characters, but their encoded form and lookalike characters can complicate sharing and security.

Use a separate contact address that does not depend solely on the domain being managed, so you can recover the registrar account if DNS or mail breaks. Document who controls the registrar, DNS provider, hosting and certificates. This avoids losing access when a team member or contractor leaves.

Diagnosing a domain problem

First check whether registration is active and the intended authoritative name servers are delegated. Then query those servers for the required record types. If the DNS answer is correct, test the web or mail service independently. Note the precise name, record type and time because caches may keep older answers for a while after an update.