Question

Explain how the format of the mark-up language differs from the document’s format,

Answer 1

A document format is a simple text without any differentiation between the elements in the text, whereas mark- up language  is a system for annotating a document in a way that is syntactically distinguishable from the text. Instructions are expressed directly by tags or "instruction text encapsulated by tags." Examples include typesetting instructions such as those found in troff, TeX and LaTeX, or structural markers such as XML tags. Markup instructs the software that displays the text to carry out appropriate actions, but is omitted from the version of the text that users see.Today, the most important markup languages are the Standard Generalized Markup Language (SGML), the Hypertext Markup Language (HTML), and the Extensible Markup Language (XML).

HTML

The Hypertext Markup Language is an SGML Document Type Definition (DTD) that was designed specifically for the World Wide Web. In essence, HTML is a set of markup codes inserted in a file that note logical structures and instruct a web browser how to display a web page's words and images.

XML

The Extensible Markup Language (XML) is a subset of SGML, whose purpose is "to enable generic SGML to be served, received, and processed on the web" through a system of notation that is unlimited and self-defining. Although XML has been designed to be compatible with HTML (as well as SGML), it is not another single, predefined markup language. It is a meta-language—a language for describing other languages—for designing markup.