markup language

markup language

Standard text-encoding system consisting of a set of symbols inserted in a text document to control its structure, formatting, or the relationship among its parts. The most widely used markup languages are SGML, HTML, and XML. The markup symbols can be interpreted by a device (computer, printer, browser, etc.) to control how a document should look when printed or displayed on a monitor. A marked-up document thus contains two types of text: text to be displayed and markup language on how to display it.

---

A set of labels that are embedded within text to distinguish individual elements or groups of elements for display or identification purposes. The labels are typically known as "tags."

For rendering (displaying and printing), markup languages indicate where font and other layout changes start and stop. For content identification, markup languages turn a text document into the equivalent of a database record in which individual data elements can be located for processing. In a database, elements are placed in a predefined structure. In a document, data elements reside in a freeform structure like text and must be identified with tags that mark their beginning and end.

It All Started with SGML
SGML is the granddaddy markup language that served as the foundation for HTML and XML. HTML is used for rendering the document, and XML is used for identifying the content of the document. See XML vocabulary, SGML, HTML and XML.