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3-1-5 Markup Language

Markup languages are a type of programming language for printing and screen display. Text (i.e. a character string) is enclosed in marks that are called tags, and attribute information is attached. Structural elements of a document (e.g., texts, paragraphs, titles, tables and diagrams) and their relationships can be easily defined.

(1) SGML (Standard Generalized Markup Language) This is a general purpose markup language that was standardized by ISO. It enables description of the logical structure, semantic structure, and attributes of a document. So, document management and data conversion can be performed easily. In SGML, the structure of a document is defined with a DTD (Document Type Definition). · 1 question

(2) HTML (HyperText Markup Language) This is a hypertext description language that extends SGML to enable it to handle not just text but also graphics, images, movies, and so on. Hypertext interconnects content with other content (i.e., web page) through a link comprising character information. HTML encloses text with a start tag and an end tag to specify character size and color, image files to be included, web pages to be linked, and so on. Although the specifications are standardized, companies that create web browsers add their own extended specifications. Therefore, some tags can only be used in browsers created by a specific manufacturer. Furthermore, CSS (Cascading Style Sheets) can be used to define only the layout of a web page that is completely separated from HTML.

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(3) DHTML (Dynamic HTML) This is an extended HTML specification. By incorporating a script written in JavaScript or VBScript into an HTML page, it enables the dynamic creation of a web page according to user operations, and the checking of user input data.

(4) XML (Extensible Markup Language) This is a derivative of SGML and HTML, and is a hypertext description language that enables bidirectional linking. It is highly suitable for the Internet environment and is often used for corporate transactions via a network. By using a DTD (Document Type Definition), users can define their own tags. Currently, a dedicated XML schema language called XML Schema is often used instead of DTD. In HTML, the end tag can be omitted in some cases, but in XML there must be a start tag and an end tag even for a null element. XSL (Extensible Stylesheet Language) can be used for style sheets in XML. · 1 question

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(5) XHTML (EXtensible HyperText Markup Language) This is a markup language that has redefined HTML, which extends SGML, by using XML. The specifications are stricter than HTML; for example, “it is not possible to leave out a tag.” XHTML Basic is intended for use on cell phones and personal digital assistants and is a subset of combined modules defined on the basis of the specifications of the modularization of XHTML.