What is XML?
XML is the abbreviation for Extensible Markup Language and a data format. This versatile markup language was created when HTML reached its limits. The big advantages of XML are the low learning effort as well as the wide distribution. XML is used to store, describe and exchange data
- A text-based data format
- Easily interpreted by machines and humans
- Can be used in many different ways
XML makes web applications more intelligent and powerful
The essence of XML lies in its name: Extensible Markup Language. XML is initially extensible. Here you can define your own tags, the order in which they appear and how they should be processed or displayed. XML also allows us to expand our idea of a document: it can be a file that resides on a file server, or a temporary data element that flows between two computer systems (as in the case of Web services). The best known feature of XML is its tags or elements. In fact, the elements that you create in XML are very similar to the elements that you have already created in your HTML documents. However, with XML, you can define your own tags. XML is a language that is very similar to HTML. However, it is much more flexible than HTML because you can create your own custom tags. However, it is important to know that XML is not just a language. XML is a metalanguage: a language that we can use to create or define other languages. For example, XML allows us to create other languages like RSS, MathML (a mathematical markup language), and even tools like XSLT. XML data can be opened and edited in a simple editor. In addition, all computers can read and write the XML format easily. XML was developed in the late 90s
Why do we need XML?
We need it because HTML was developed specifically to describe documents to be displayed in a web browser and not much more beyond that. It can be cumbersome if you want to display documents on a mobile device or perform even slightly complicated tasks, such as translating the content of one language into another. The sole purpose of HTML is to allow anyone to quickly create Web documents that can be shared with others. But XML isnt just for the Web-it can be used in a variety of different contexts, some of which may have nothing to do with how people interact with content (for example, Web services use XML to send requests and responses back and forth). HTML rarely (if ever) provides information about how the document is structured or what it means. To the layperson, HTML is a presentation language, while XML is a data description language. XML, like HTML, is made up of the so-called tags, which are placed between angle brackets. With XML you can define your own tags. How such a tag should look like is defined, but not what it means. The tags can be nested within each other. Thus a hierarchy can be created. If required, a tag has one or even more parameters. The parameters always have a name and a value. The only disadvantage is the data overhead, unlike a binary format. This means that the structure stored in XML format requires a little more memory than necessary. Therefore, it can only be processed more slowly. XML is regularly used to export and import various application data. For example, customer databases can be represented quite well in XML format. XML is platform and language independent: The main advantage of XML is primarily that you can use it to convert data from a program like Microsoft SQL to XML and then share it with other programs and platforms. You can communicate between two platforms, which is generally very difficult. The main factor that makes XML really powerful is its international acceptance. Many companies use XML interfaces for databases, programming, mobile phones, office applications and much more. The great acceptance is due to its great platform-independent functionality