A domain is a unique name used to identify a website or another Internet resource, allowing users to access it without having to remember a numerical IP address. For example, in the address example.com, the domain is example.com.
Domain names work through the DNS (Domain Name System) — a distributed system that maps human-readable names to the IP addresses of servers. When a user enters a domain name in a browser, DNS helps determine which server the request should be sent to.
What Is a Domain Name Made Of?
The structure of a domain name is read from right to left and can include several levels. For example, in blog.example.com:
- .com — the Top-Level Domain (TLD)
- example — the second-level domain
- blog — a subdomain
Top-level domains can be generic (gTLDs), such as .com, .org, and .net, or country-code top-level domains (ccTLDs), such as .de for Germany, .fr for France, or .uk for the United Kingdom. There are also newer thematic domain extensions, such as .cloud, .tech, and .shop.
How Does a Domain Work?
A domain itself does not contain a website and is not a server. It is a registered name that is associated with specific Internet resources through DNS.
When a user opens a website, the browser requests DNS information for the specified domain. The DNS system finds the corresponding IP address, after which the browser establishes a connection to the server hosting the resource.
DNS records are used to configure these associations:
- an A record maps a domain name to an IPv4 address
- an AAAA record maps it to an IPv6 address
- an MX record specifies mail servers
- a CNAME record allows one domain name to point to another
What Are Domains Used For?
The most obvious use of a domain is as a website address, but its functions are not limited to websites. A single domain can be used simultaneously for a website, corporate email, APIs, cloud services, and other resources. For example, an organization might use:
- example.com for its main website
- mail.example.com for its email infrastructure
- api.example.com for its API
- support.example.com for its technical support portal
This structure makes it possible to separate services while keeping them within a single domain namespace.
Domain Registration and Management
To use a domain name, it must be registered through an accredited domain registrar. Registration is usually valid for a specific period and must subsequently be renewed.
When registering a domain, the registrant obtains the right to use the selected domain name but does not purchase it permanently. If the registration is not renewed on time, the domain may eventually become available to other users after the applicable registry-defined periods have expired.
Domain management includes configuring DNS servers and records, renewing the registration, updating contact and technical information, and, when necessary, transferring the domain between registrars.
Domain vs. URL vs. Hosting: What Is the Difference?
These concepts are related but refer to different things. A domain is the name of an Internet resource, such as example.com. Hosting provides the computing resources where a website and its data are stored. A URL (Uniform Resource Locator) is the complete address of a specific resource.
For example, in the URL https://example.com/products/server, the domain is example.com, while the entire address is the URL.