What is a top level domain (TLD)
Top-level domains were initially created in order to organize and catalog the different web pages depending on the country, the category (or content it will have) and multi-organizations. In this way, just by seeing the TLD domain of any URL we will be able to get an idea of the content that the page will have.
For example, if a page has the TLD. We will know instantly that it is a page from Spain, in the same way that if we visit a web page .gov we will know that it has a relationship with the government.
When we are going to register any web domain, the registrars themselves (all of them under the control of ICANN) allow us to choose the TLD we want from a wide list of them. This allows us, for example, that if a .com domain is already registered we can buy the .net or .es.
The truth is that it is not usually controlled if a web is really associated with the chosen TLD, and it is the task of the administrators themselves to be able to choose the right one, since, if they do not do it, in the long run it may not work out well. If a personal page is registered with a .com domain, designed especially for businesses, it would not be well done, although no one would prevent it. The same as if we register our page, in Spanish, under a .us or .uk domain.
What is a top level domain and What is a TLD?
The acronym TLD comes from Top Level Domain or top level domain . But, on the other hand, what is a domain? It is nothing but a name that identifies a specific machine. When we access a Web page like this, a request is made first to the DNS system to know to which machine we are making the request.
The top level domain name TLDN of Xataka ON would be com. In that way, a TLD would be, for example com, o net, o info, o es. Not all are gTLDs.
What types of TLDs exist?
When the system began to take shape in the 1980s, two categories of TLD were distinguished.
- On the one hand, gTLDsor generic top-level domains. Initially they were seven: com, net, info, gov, mil, edu, int.
- On the other hand, the ccTLDor country code top level domain . These would be the territorial domains, which would have the name of each country’s abbreviation according to ISO-3166 (with exceptions, such as Great Britain). To this group belong domains such as es(for Spain), fr(for France) or tv(for the island of Tuvalu).
The Internet has grown a lot since the 1980s and, as a result, has grown. Currently there are 22 gTLDs and 293 ccTLDs , according to Wikipedia.
As I say, gTLDs are generic domains. These can be distinguished in several groups:
- Non-sponsored, which are administered directly by ICANN. An example can be com.
- Sponsored, which are managed jointly by ICANN and the private entity that, in addition, establishes restrictive policies for this type of domains. As examples of sponsored gTLDs aero, which is restricted by the Society Internationale de Telecommunications Aeronautics for the aeronautical industry. This is the case also of cat, gland sue.
There is also a single domain of infrastructure , arpaadministered by IANA and, if not disabled yet, is because it has very specific uses related to the infrastructure of the Internet.
What are the main TLDs?
Of the generics, we could highlight, for example:
- .biz, for business.
- .com, for commercial purposes.
- .info, for general information.
- .int, for international organizations.
- .mobi, for mobile sites
- .name, for personal and individual pages.
- .net, for whatever, although its original purpose was to point to “umbrella” sites (portal to access smaller sites).
- .org, for non-profit organizations.
- .pro, for professionals.
- .tel, for contact data (it is stored directly in the DNS).
There is also a ccTLD for each country, although some are used for very different purposes, such as .am , .fm or .tv , which are used in radio and television, .eu that has been used to spread the Basque culture, .gl (same, but for Galicia), .md (used for doctors) or .tk for free domains.
There are 6 types of top-level domains (TLD)
Currently there are a total of 6 main types of top-level domain, TLD, all controlled by ICANN (Internet Corporation for Assigned Names). These are:
- Country Code TLDs (ccTLD) . These are the ones that identify websites based on their country, such as .es for Spain or .uk for the United Kingdom.
- Generic Top Level Domain (gTLD) . This is where the generic names of the domains are included, the most used, such as .com, .org, .info or .net. Currently there are more than 1200 different types.
- Infrastructure Top Level Domains , better known as harp domains. They are used only for Internet maintenance and are responsible for controlling routing and routing.
- Sponsored Top Level Domains . Domains associated with institutions, such as .edu, .museum, .jobs, .mobi or .gov, among others. These domains are controlled and can only be used by these institutions.
- Creative Top Level Domains . Domains for creative platforms and pages, such as .tv, .name, .me, .expert and .guru.
- Internationalized Top-Level Domains . Domains reserved for native alphabets from other countries.
In addition, there are also other domains, such as .invalid, .localhost and .test, designed to be used in test environments but that can not succeed.
A complete list of Country Code Top Level Domain (ccTLD) extensions is listed below (in alphabetical order).
- a. a. a. a. a. a. a. a. a. a. a. a. a. a. a. a. a. a. a. a. b a. bb. .bi .bj .bm .bn .bo .br .bs .bt .bw .by .bz .ca .cc .cd .cf .cf .cg .ch .crc .ck .cl .cm .cn .co .cr .cu .cv .cx .cy .cz .de .dj .dk .dm .do .dz .ec .er .es .et .eu .fi .fj .fk .fm .fo .fr .ga .gd .gf .gg .gq .gq .gr .gs .gg .gy .gy .hk .hm .hn .hr .ht .hu .id .ie .il .im .in .io .iq .ir .is .je .jm .jo .jp .ke .kg .kh .ki .km .kn .kp .kr .kw .ky .k .la .lb .lc .lk .lk .lr .ls .lt mr .mr .mr .mr .mk .ml .mr .mn .mo .mp .mq .mr .ms .mt .mu .mv .mw .mx .my .mz. na .nc .ne .nf .ng .ni .nl .no .np .nr .nz .nz. om .pa .pe .pf .pg .ph .pk .pl .pn .pr .ps .pt .pw .py .qa .re .ro .rs .rw .sa .sb .sc .sd .se. sg .sh .sk .sl .sm .sn .s .sv .sy .sz .tc .td .tf .tg .th .tj .tk .ttl .tm .tn .tr .tt. tv .tz .ua .ug .uk .us .uy.
Domain vs. Subdomain
For example, take mail.yahoo.com – yahoo.com is the domain, in this case mail.yahoo.com is the subdomain.
Domains must be unique (e.g. there can only be one Yahoo.com) and must register with your domain registrar (e.g. NameCheap and hover ); For subdomains, users can freely add to the top of an existing domain as long as the web host provides the service. Some are used to organize website content into other languages or other categories, usually by saying that the subdomain is a ‘third-level’ domain in the sense of simply “subfolders” under the domain root directory.
However, this does not apply in many cases, including search engines. It is a known fact that search engines (i.e., Google) process subdomains in different domains separate from the primary domain.