A printing method invented in 1937 by the American patent lawyer Chester F. Carlson that functions in the following manner: a drum coated with a photo semiconductor is charged up and then partially discharged by a motif projected onto it. Dark areas retain their charge and toner applied to these areas remains in place. The image created in this way is then transferred to paper and fixed with heat. Originally designed for copiers, the technology is now also used for laser printers and digital printing systems.
A symbol language used to describe the structure of documents. XML is superficially similar to HTML, the primary difference being that the symbols (“tags”) used in XML can be selected with a larger degree of freedom, while they are fixed in HTML. This feature allows special forms of XML to be generated for virtually any type of application. XML is essentially a slimmed-down form of the SGML (Standard Generalized Markup Language) document description language defined in ISO 8879 and was created for transmitting richly structured documents via the World Wide Web. The International World Wide Web Consortium is responsible for the standardization of XML.