Extensible Markup Language, or simple XML became a W3C recommendation on February 10th 1998.
XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. It is defined in the XML 1.0 Specification and produced by the W3C, and several other related specifications. It is a textual data format with strong support via Unicode for the programming languages of the world. Although the design of XML focuses on documents, it is widely used for the representation of arbitrary data structures, for example in web services.
XML is designed to transport and store data.
According to W3C, XML is a software and hardware independent tool for carrying information.
XML documents consist entirely of characters from the Unicode repertoire. Except for a small number of specifically excluded control characters, any character defined by Unicode may appear within the content of an XML document. The selection of characters that may appear within markup is somewhat more limited but still large. XML includes facilities for identifying the encoding of the Unicode characters that make up the document, and for expressing characters that, for one reason or another, cannot be used directly.
Reference Source : Wikipedia, the free encyclopedia.
Take Away:
- XML vs. XHTML/HTML. XML was designed to describe date, whereas XHTML/HTML was designed to display data. Therefore, XML is not a replacement for HTML;
- XML tags are not predefined. The developer should defines his own tags;
- XML is designed to be self-descriptive. It is just information wrapped in tags. Therefore, to give a meaning for a XML document a developer must write code to send, receive, or display XML data.