What is a domain name?
In short, a domain name is a name or address of a website or a server on the internet which can be used to locate the website or server instead of calling or finding it using an IP address through the internet.
A domain name is an identification string or text that defines a realm of administrative autonomy, authority, or control within the Internet. Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a network domain, or it represents an Internet Protocol (IP) resource, such as a personal computer used to access the Internet, a server computer hosting a website, or the website itself or any other service communicated via the Internet. In 2017, 330.6 million domain names had been registered. A domain name can have any combination of letters and numbers.
What is a Domain Name Extension or TLD?
A domain name can be used with the combination of various domain name extensions or TLDs, such as com net org edu and more. Domain names are formed by the rules and procedures of the Domain Name System (DNS). Any name registered in the DNS is a domain name. Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, info, net, edu, and org, and the country code top-level domains (ccTLDs) bd, au, us, ca. Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources, or run web sites.
The domain name must be registered before you start using it. Every domain name is unique. You can use multiple domains for a single internet protocol (IP), website, or server. But you can’t use a single domain name for multiple IPs, websites, or servers. If someone types in www.zerowtech.com, it will come to our website and no one else’s website or server. The registration of these domain names is usually administered by domain name registrars who sell their services to the public.
The price of a domain name typically runs between $10-25 per year.
Second-level and lower level domains
Below the top-level domains in the domain name hierarchy are the second-level domain (SLD) names. These are the names directly to the left of .com, .net, and the other top-level domains. As an example, in the domain example.co.uk, co is the second-level domain.
Next are third-level domains, which are written immediately to the left of a second-level domain. There can be fourth- and fifth-level domains, and so on, with virtually no limitation. An example of an operational domain name with four levels of domain labels is sos.state.oh.us. Each label is separated by a full stop (dot). ‘sos’ is said to be a sub-domain of ‘state.oh.us’, and ‘state’ a sub-domain of ‘oh.us’, etc. In general, subdomains are domains subordinate to their parent domain. An example of very deep levels of subdomain ordering are the IPv6 reverse resolution DNS zones, e.g., 220.127.116.11.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa, which is the reverse DNS resolution domain name for the IP address of a loopback interface, or the localhost name.
Second-level (or lower-level, depending on the established parent hierarchy) domain names are often created based on the name of a company (e.g., bbc.co.uk), product, or service (e.g. hotmail.com). Below these levels, the next domain name component has been used to designate a particular host server. Therefore, ftp.example.com might be an FTP server, www.example.com would be a World Wide Web server, and mail.example.com could be an email server, each intended to perform only the implied function. Modern technology allows multiple physical servers with either different (cf. load balancing) or even identical addresses (cf. anycast) to serve a single hostname or domain name, or multiple domain names to be served by a single computer. The latter is very popular in Web hosting service centers, where service providers host the websites of many organizations on just a few servers.
The following list shows the first 20 domains with the dates of their registration:
- symbolics.com — 15/03/1985
- bbn.com — 24/04/1985
- think.com -24/05/1985
- mcc.com — 11/07/1985
- dec.com — 30/09/1985
- northrop.com — 07/11/1985
- xerox.com -09/01/1986
- sri.com — 17/01/1986
- hp.com — 03/03/1986
- bellcore.com — 05/03/1986
- ibm.com — 19/03/1986
- sun.com — 19/03/1986
- intel.com — 25/03/1986
- ti.com — 25/03/1986
- att.com — 25/04/1986
- gmr.com — 08/05/1986
- tek.com — 08/05/1986
- fmc.com — 10/07/1986
- ub.com — 10/07/1986
- bell-atl.com — 05/08/1986
A fully qualified domain name (FQDN) is a domain name that is completely specified with all labels in the hierarchy of the DNS, having no parts omitted. Traditionally an FQDN ends in a dot (.) to denote the top of the DNS tree. Labels in the Domain Name System are case-insensitive, and may therefore be written in any desired capitalization method, but most commonly domain names are written in lowercase in technical contexts.
Learn more on Wikipedia.