Concept in Definition ABC

Since the first computers, these machines have worked with structured data, although now they are beginning to be able to do so with unstructured data thanks to the artificial intelligence.

To structure data, you need some kind of language descriptive that allows defining the structure and indicating to which fields each data belongs. This language allows computer applications to properly recognize and present data, and can delimit the Format of the files in which they are saved.

XML is one of these languages ​​that allows you to define data, although it goes further than just this.

The XML (acronym for Extensible Markup Language) is a markup language that allows us to define a data structure, as well as a document to make it readable both to a computer and to a human being.

Going forward a bit, I give you an example of its use: the language HTML with which web pages are built can be defined as a subset of XML.

Although we are talking about language, purely XML is a metalanguage, since its syntax is defined, but not the words with which it is materialized, so that each one can define a subset of the XML for a task concrete. This is how HTML can be defined as a subset of XML.

Its use extends to applications such as text, databases or spreadsheets, in general all those tasks that require structuring (hence, before talking about structured data) and / or a presentation.

Each mark in each subset of XML begins with the sign.

In this way, we can differentiate the marks of the text and data that they enclose (and the computer program that manages them can also differentiate them).

In addition, there are tags opening and closing. the difference is that the closing ones put the symbol / to the word enclosed between .

At this point, let's take an example of using XML: a very simple phone book built with tags of this metalanguage that we have made to measure:

Jaime Perez

666 000 000

Juan Cabo

666 000 111

Ana Lopez

666 000 222

We could even create a program that would manage these records and present them in an appropriate way.

In practice, XML is increasingly used, and we use it without realizing it in the main office applications, such as Microsoft Office and LibreOffice.

The formats of file Both of these have long been subsets of XML, which simplifies the loading and presentation of files generated with one of these in the other. However, the fact that the presentations are not always the same resides in the fact that the final presentation of the data falls on the program.

An XML document has more resources and sections, such as comments, or content models, but its essence is what I have explained in the example.

From here, it becomes as complicated as our needs, although, in fact, XML will hardly be seen by a Username end that, yes, you can work without realizing it with this format.

Fotolia photos: Maksim Kabakou / Kitti

Themes in XML