Hypertext Markup Language (HTML) 

HTML enables embedding of scripts like JavaScript to influence web pages' behavior and content, while CSS determines their appearance. Since 1997, the W3C has advocated for using CSS instead of presentational HTML. HTML5, a variant of HTML, supports video and audio display, primarily through the element and JavaScript.

HTML elements form the fundamental components of HTML pages, allowing for the incorporation of images and interactive forms. They facilitate the creation of structured documents through the use of tags, which define the semantics of headings, paragraphs, lists, links, and more. While browsers do not show these tags, they utilize them to process and display the page's content.

History

In 1980, physicist Tim Berners-Lee, working as a contractor at CERN, developed ENQUIRE, a document-sharing system for researchers. In 1989, he proposed an Internet-based hypertext system and outlined HTML, writing the necessary browser and server software by late 1990. That year, he collaborated with CERN engineer Robert Cailliau on a funding request, although the project was not officially adopted. In his 1990 notes, Berners-Lee highlighted various applications of hypertext, starting with encyclopedias.

Markup

HTML markup consists of several key components, including those called tags (and their attributes), character-based data types, character references and entity references. HTML tags most commonly come in pairs like <h1> and </h1>, although some represent empty elements and so are unpaired, for example <img>. The first tag in such a pair is the start tag, and the second is the end tag (they are also called opening tags and closing tags).

The following is an example of the classic "Hello, World!" program: