Domain names are structured in a hierarchical system, resembling an inverted tree, and are managed through a global system called the Domain Name System (DNS). Here’s a detailed breakdown:
Domain Name Hierarchy
Domain names are organized via subdomains which are subordinate levels of the Domain Name System root domain. This means they follow a layered structure, with each level providing more specific information:
- Root Domain: This is the top of the hierarchy, often represented as a period (.), although it’s usually not visible in website addresses.
- Top-Level Domains (TLDs): These are the first-level set of domain names and sit directly beneath the root domain. They include:
- Generic Top-Level Domains (gTLDs): Examples are
.com,.net, and.org. These are generally used for broad categories of websites. - Country Code Top-Level Domains (ccTLDs): These TLDs are associated with specific countries, like
.usfor the United States,.ukfor the United Kingdom, or.cafor Canada.
- Generic Top-Level Domains (gTLDs): Examples are
- Second-Level Domains: These are the names that are registered, such as
googleingoogle.comorwikipediainwikipedia.org. - Subdomains: These are divisions within the second-level domain, like
blog.example.comorshop.example.com. They allow for further organization of a website.
Domain Name Management
The overall management of domain names is complex, involving different entities:
- ICANN (Internet Corporation for Assigned Names and Numbers): This non-profit organization is responsible for coordinating the DNS and managing TLDs. They set policies and guidelines for the domain name system.
- Domain Registries: These organizations manage specific TLDs. For example, Verisign manages the
.comand.netTLDs. Registries maintain the master databases for their TLDs. - Domain Registrars: These are companies that sell domain names to the public. Registrars interact with registries to register and manage domain names on behalf of individuals and businesses. Examples include GoDaddy and Namecheap.
- Domain Name System (DNS): This global system acts as a phonebook for the internet, translating human-readable domain names into IP addresses that computers use to locate web servers.
The Registration Process
- Check Availability: Before registering, you check if a domain name is available.
- Choose a Registrar: You select a domain registrar.
- Register the Domain: You purchase and register the domain name through the registrar.
- DNS Configuration: You configure DNS records to point the domain name to your web server.
- Renewal: You renew your domain registration before it expires to maintain ownership.
Key Aspects of Management
- Delegation: Management involves delegating authority for subdomains to different name servers.
- Resolution: The system translates domain names into IP addresses through queries within the DNS.
- Record Management: Registrants manage various DNS records, like A records (for IP addresses) and MX records (for email).
Example
Let’s take the domain name www.blog.example.co.uk:
| Component | Description |
|---|---|
. (implied) |
Root domain |
uk |
Country code TLD (ccTLD) |
co |
Second-level Domain (often a commercial entity) |
example |
Registered domain name |
blog |
Subdomain |
www |
Common subdomain for the World Wide Web |
In conclusion, domain names are organized hierarchically using subdomains under the DNS root domain, with TLDs being the first level, and their management relies on various actors, including ICANN, registries, and registrars, ensuring seamless operation of the Internet.
