All about URLs: What words can’t we use?

When we turn on the computer and open the browser to enter a web page, what we are doing is connecting our equipment to a server where the web we want to enter is hosted. Just as when we call by phone, to connect with the other terminal, we have to dial a number, on the Internet this step is solved with the so-called Internet addresses, or URL (Uniform Resource Locator, uniform resource locator in Spanish)

These URLs are the name that is assigned to a specific Internet address, which we have to go to to enter the page we want. If the Internet addresses did not exist, we would have to remember the IP address of the server where said web page is hosted, which would greatly complicate navigation. We would have to remember thousands of numbers instead of words much easier to memorize, like or

As you will see, URLs are made up of different parts that we are going to detail below, such as the protocol, the domain name, a general or specific ending … Nothing is chosen at random, beyond the name that each one wants to give to your web domain. And in this aspect there is not total freedom either, since there are characters that we will not be able to use.

HTTP and HTTPS protocols

Although it is not necessary to write it many times, it is a fundamental part of Internet addresses. They may be invisible characters if we surf the Internet and we do not pay attention to them, but they are more important than it may seem to us and that simple difference of one letter between one and the other implies many changes.

The HTTP protocol is the acronym for Hypertext Transfer Protocol, which when translated is the protocol that allows information to be transferred over the Internet, that we can connect to other computers at other addresses and read the information they offer us. For many years this protocol has been the most widely used, but as the use of the Internet has progressed globally, other needs have arisen, especially security, which have led to another protocol, HTTPS.

The difference between one and the other is clear, the S for Security. The use of the web has changed and now we buy much more over the Internet, we offer our bank or other data on our computer and a protocol that offered greater security was necessary when we carry out this type of operation. When we access an HTTPS website, we will also see a padlock next to the address, a symbol of greater security. What this protocol does is prevent the information that we transfer when we connect to these pages from being intercepted.

Parts of the URL

What parts are in the URL or Internet address behind HTTP or HTTPS? The www prefix, the domain or the endings …

Www prefix

Although it is not necessary to type it, the prefix www (World Wide Web) is present in Internet addresses. You have seen it countless times and we usually type it in the browser bar before writing the exact address of the page that interests us. Is always.

It is a domain that tells us that we are accessing a web server, just as if we were connecting to a file transfer server, this prefix would be ftp. Almost all browsers understand that even if you omit their typing, those three ws are present in the Internet address.


A domain name is the most important part of the Internet address, it is the name that we will have to memorize in order to access the web page that we want. A domain name is the name associated with the IP address of the server where the web page is hosted. If these names did not exist, we would have to memorize the IP address numbers to be able to access Amazon, YouTube, Twitch, Adslzone …

These names are chosen by the people responsible for the websites in question , it is a domain name that will identify your website to the world and that will make it unique and identifiable on the network.

In this sense, a fundamental element of the Internet is the DNS or Domain Name System. The DNS are responsible for translating the domain into an IP address. Actually, when we type an Internet address in the browser bar, what we are doing is asking a database, a DNS, what is the IP address of that web page. The DNS returns the information to us and allows us to connect.


Although it is incorporated into the domain name, the endings of these are not chosen at random . These are divided into two groups, the so-called ccTLDs (country code top level domain) that correspond to the identification of each territory, such as .es domains for services from Spain or .mx for Mexico; and the so-called gTLDs (generic top level domain) for commercial or organizational services.

Examples of top-level domain names

  • .ad, for Andorran services
  • .ar, for Argentina services
  • .am, for Armenia services
  • .at, for Austrian services
  • .asia, the region of Asia
  • .au, for Australian services
  • .be, for Belgium services
  • .biz intended for business use.
  • .bo, for Bolivian services
  • .br, for Brazilian services
  • .bg, for Bulgarian services
  • .ca, for Canadian services
  • .cat, for pages related to Catalan culture and language.
  • .ch, for Swiss services
  • .cl, for services in Chile
  • .co, for Colombian services
  • .cn,. 中國 (in traditional Chinese) and. 中国 (in simplified Chinese) for China services
  • .com, of any subject, usually used for commercial activities.
  • .cr, for Costa Rican services
  • .cu, for Cuban services
  • .cz, for Czech Republic services
  • .de, for Germany services
  • .dk, for Danish services
  • .do, for Dominican Republic services
  • .ec, for Ecuador services
  • .edu, for Education services
  • .eg and .مصر (in Arabic), for Egyptian services
  • .es, for services in Spain
  • .eu, for European Union countries
  • .eus, for pages related to the Basque language and culture.
  • .fi, for Finnish services
  • .fm, for FM radio station pages.
  • .fr, for French services
  • .fo, for Faroe Islands services
  • .gal, for pages related to Galician culture and language.
  • .gov and .gob, for government and public entities.
  • .gr and .ελ (in Greek) for Greek services
  • .gt, for Guatemala services
  • .hn, for Honduras services
  • .hr, for Croatian services
  • .info, for information.
  • .int, for international entities.
  • .il, for Israel services
  • .ir and for Iran services
  • .it, for services in Italy
  • .jobs, for employment and human resources departments in companies.
  • .jp and. み ん な (in Japanese), for Japanese services
  • .kp, for North Korean services
  • .kr and. 닷컴 (in Korean) for South Korean services
  • .lat, the Latin American region
  • .lt, for Lithuanian services
  • .lu, for Luxembourg services
  • .ma, for Moroccan Flag services Morocco
  • .me, for Montenegrin services
  • .mil, for the United States Department of Defense.
  • .mobi, for mobile phone companies or mobile services.
  • .museum, for museums.
  • .mx, for Mexico services
  • .ni, for Nicaraguan companies and services
  • .no, for Norwegian companies and services
  • .name, for people’s names
  • .net, for network infrastructure
  • .nl, for Netherlands pages
  • .nz, for New Zealand pages
  • .onion, for anonymous sites
  • .org, for organizations
  • .pa, for Panama pages
  • .pe, for Peru pages
  • .pl, for Polish pages
  • .pro, for professionals with a university degree.
  • .ps, for Palestine pages
  • .pt, for Portugal services
  • .py, for services in Paraguay
  • .ro, for Romanian flag services Romania
  • .rs and .срб (in Serbian), for Serbian Flag services Serbia
  • .ru and .рф, for Russian services
  • .sa for Saudi Arabia pages
  • .se, for Swedish services
  • .sg, for Singapore services
  • .si, for Slovenian services
  • .sv, for services in El Salvador
  • .tel, for internet communication services.
  • .tk, for pages with their own domain and server.
  • .tw,. 台灣 (in traditional Chinese) and. 台灣 (in simplified Chinese), for Taiwan services
  • .travel, for pages of the travel and tourism industry.
  • .tv, for television stations.
  • .ua, for Ukrainian pages
  • .uk, for UK pages
  • .uy, for services in Uruguay
  • .va, for Vatican City services
  • .ve, for Venezuela services
  • .web is an unofficial top-level internet domain.
  • .ws for Samoa pages
  • .za for South African pages

What cannot be used in a domain

There are domain names that are prohibited, that is, you cannot open a web page and name it whatever you want. There are a number of restrictions.

Forbidden words

Obviously you will not be able to use a domain name that is already in use, because it is owned by another person or organization. You will have to be careful not to incur a violation of the Trademark Law. But there is also a list of words that are prohibited and that you will not be able to use even if you like them or even if you consider that they have been used as a joke or irony. Not everything goes when choosing a domain.

You will not be able to use bad language, sexual, insults or those words that resemble official domains or that can create confusion.

Prohibited letters

Domains can be made up of letters and numbers, from A to Z and from 0 to 9 , allowing many different combinations. But there are a number of limitations, because characters or combinations that are prohibited. For example, you will not be able to use spaces, you will not be able to use special characters like &,%, $, /, (,), =,?, ¿, “Or! and you will not be able to put points either, since the point is reserved for the termination of the domain name, such as .com or .es. Yes you can use hyphens, but not two in a row and they cannot be in the first or last position.

What about the ñ? You have to bear in mind that keyboards that are not Spanish, the ñ is not included, so if you want them to access your website you should look for an alternative, either using it or not any other combination you prefer.

by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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