URL

We explain what a URL is, what it is for. Also, how they are classified and what their parts are.

What is a URL?

In computing, the URL (acronym for Uniform Resource Locatori.e. “Uniform Resource Locator”) It is a specific sequence of characters that identifies and allows you to locate and retrieve specific information on the Internet

Just as in real life each home or business has a postal address, on the Internet each resource (image, video, text, audio or web page) also has an associated URL address, which is necessary to know to have direct access to that information.

The URL is what you type into the web browser box to visit a particular web page, commonly referred to as an “address.” Each resource present on the Internet has, in principle, a unique and specific URL address. It is possible, however, that when the location resources change, the associated address also changes, and in these cases we usually speak of a “broken” URL, that is, one that no longer effectively leads to its associated resource.

For example, Google is located at the URL https://www.google.com. However, their national versions have slightly different addresses, such as:

• https://www.google.com.ar (Argentina)
• https://www.google.com.ve (Venezuela)
• https://www.google.com.br (Brazil)

URLs first appeared in 1991 to allow online publishers to hyperlink to content hosted online. Since 1994, the URI (acronym for Uniform Resource Identifier or “Uniform Resource Identifier”), composed of both a URL and a URN (acronym for Uniform Resource Name or “Uniform Resource Name”). However, in common speech we still talk about URLs.

See also: Software

What is a URL for?

Each URL is a specific address on the Internet, so that by knowing it you can directly locate different information online. Thus, by entering the URL of an image you can view it, while that of a specific file will allow you to download it and that of an online program to execute it.

On the other hand, Internet search engines manage the URLs of web pages (along with other location data) to identify which ones match the information requested, and that is why some pages are easier to find. than others with this system.

Characteristics of a URL

Some characteristics of URLs are:

• Accuracy. URLs consist of an exact sequence of characters, so they must be typed precisely to return the expected result. An error in the chain is enough to prevent the desired information from being accessible.
• Sequence. URLs are an ordered sequence of information, which must be entered in a precise sequence, like a postal address.
• Uniqueness. Each URL is unique for a resource or web page, there are no two different ones that lead to the same element (although there may be many versions of the same element, for example, many different copies of the same photograph, each with its respective URL ).

Parts of a URL

A URL can be decomposed into a sequence of directions, each referring to a specific aspect of the location of the desired resource.

The most common parts of a URL are:

• Network protocol. It is the initial segment of a URL, whose job is to tell the system what type of connection it should establish and what is the specific language that will be spoken with the computer or computer network that will provide the requested information. Http, Https, mailto and ftp are the main web protocols that head a URL.
• Subdomain. It is the type of support services in which online information is found, of which the World Wide Web (www.) is the most popular.
• Domain It is the “name” of the server you are trying to contact, that is, the name of the person who has what you are looking for. Furthermore, the domain expresses the type of service provided (commercial (.com), educational (.edu)) and the country to which it belongs (Argentina (.ar), Brazil (.br), Italy (.it)). These last references of the domain are known as TLD (Top Level Domain or “Domain Extension”).

However, it is common to find other accessory but also significant parts in a URL address, such as:

• Port. It is the technical “door” of entry to the web server, that is, the specification of where the entry to the destination computer is carried out. It is usually expressed in terms like :80 or :443.
• Route. It is the exact address of the resource sought within the server, usually expressed as a set of parameters separated by slashes (/), periods (.) or other specialized signs.
• Additional parameters. Sometimes a URL may contain additional parameters to further specify how the searched information should be retrieved. These are usually keys (keys) and values ​​(values) separated with an ampersand (&), or other references that indicate colors or ways to display data.
• Anchor. It is a descriptor that, introduced with the pound symbol (#), specifies to the system which fragment of the information presented should be highlighted or deserves special treatment. For example, in the case of inline text, the browser will scroll to the location indicated by the anchor.

URL Types

Two types of URLs can be differentiated, based on how recognizable their characters are by the user. Thus, we can distinguish between:

• Semantic URLs. They are those in which the user can quickly and directly deduce which resource they lead to and obtain information about it. They are normally written in natural language. For example: http://ejemplosdeURL.com or http://miprogramafavorito.org
• Non-semantic URLs. They are those that are not expressed in a simple and recognizable way, but rather have technical aspects that are difficult to remember. For example: http://www.xyz.com/menu/idle.php_?page=menu or http://itpgh.org/site/main.html

References

• Ince, D. (2002). Internet Dictionary. Complutense Publishing House.
• Plá Santamaría, D. (2005). Location of specific information on the web. Editorial of the Polytechnic University of Valencia.
• Volle, A. (2023). URL (computer science). The Encyclopaedia Britannica. https://www.britannica.com/