What Is XML?

Mychelle Blake
What is XML

If you've done any work with websites, you're probably familiar with markup languages such as HTML. Another useful markup language is XML, which can be used for storing and sharing data and creating more dynamic websites.

XML Is Powerful

XML stands for Extensible Markup Language. The difference between HTML (hyper text markup language) and XML is that you can actually create and organize tags in XML. This makes XML much more flexible and powerful than HTML, and it can be used for many things aside from simply displaying information on a web page.

XML Is Semantic

One of the primary uses of XML is to categorize data and make it shareable. The data in an XML file is called "semantic" data, which means it can clearly be understood by a programmer, designer, and even sometimes the end user.

XML Is Self-Defining

XML files are often described as "self-defining," which means you can look at the data in the file and understand how it is structured and what it contains. For example, to understand an HTML file, you would need to know what tags for elements such as <h1>, <p>, and <div> mean. An XML file's tags would actually describe the data. In other words, for a file containing blogs you might see tags that say <title>, <author>, <blogtext>, etc. Of course, as an XML file becomes more complex and is used for communication with other applications, it becomes more difficult for a layperson to understand at a glance.

The Many Uses of XML

You can use XML for many different applications:

  • One of the most common uses is with Content Management Systems like WordPress. If you've ever downloaded a WordPress site, you'll see that the data is held in an XML file format.
  • Template files can be created in XML as well and downloaded and used to create websites on programs such as Blogger, LiveJournal and WordPress.
  • XML is also often used with data calls to website databases to run applications.
  • An area that many users don't realize involves XML files is Microsoft Office, which saves all Office files in XML. When you see an "x" in a Microsoft document extension, i.e. .docx, .xlsx, this means the file is saved in "Open XML."
  • MusicXML is a form of XML file that stores the data for sheet music. It has become a primary way of sharing sheet music digitally and can be read by over 200 music-related applications, such as popular programs Cubase and Symphony Pro.

What Is Sitemap XML?

A common use of XML is the creation of sitemaps for a site to be found in search engines. An XML sitemap helps crawlers for Google, Bing and other search engines to view the information on your site, so it can be displayed in user searches. An XML sitemap can be dynamic, which means it presents updated information on your site, unlike a static .HTM or .HTML file sitemap.

What Is an XML Feed?

XML feeds are used in Really Simple Syndication (RSS), which is a way of providing readers of a digest of your website. Websites that contain regularly updated pages, such as a magazine or blog site, are big users of RSS feeds. XML feeds are also used by digital marketers to send information to search engines about advertisers to have their ads displayed on various websites.

What Is an AML File?

One of the many uses of XML is to create other languages with it. For example, Microsoft Assistance Markup Language (MAML) was created with XML. MAML files have the .AML extension and these files are used to facilitate the Microsoft Windows operating system and online help for users. It first came about with the Windows Vista operating system in 2007.

What Is AJAX?

AJAX stands for Asynchronous JavaScript and XML. This tool is used to update web pages when new data is brought in, but the entire page does not need a refresh, thereby making the page and site work faster. XML is used in AJAX for the server data, although sometimes other files are used instead, such as JSON and plain text.

A Useful Item for Your Toolbox

XML is a very useful tool to have in any web developer's toolbox. It makes sharing, sending and updating data more efficient and can increase the speed and visibility of your website.

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What Is XML?