HTML, which stands for HyperText Markup Language, is the predominant markup language for web pages. It provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes, and other items. It allows images and objects to be embedded and can be used to create interactive forms.
HTML markup consists of several key components, including elements (and their attributes), character-based data types, and character references and entity references. Another important component is the document type declaration, which specifies the Document Type Definition. As of HTML 5, no Document Type Definition will need to be specified, and will only determine the layout mode .
The Hello world program, a common computer program employed for comparing programming languages, scripting languages, and markup languages is made of 9 lines of code in HTML, albeit Newlines are optional:
HTML5 is currently being developed as the next major revision of HTML (HyperText Markup Language), the core markup language of the World Wide Web. HTML5 is the proposed next standard for HTML 4.01, XHTML 1.0 and DOM Level 2 HTML. It aims to reduce the need for proprietary plug-in-based rich internet application (RIA) technologies such as Adobe Flash and Microsoft Silverlight. In common usage, HTML5 may also refer to the additional use of CSS3, as both technologies are under development in parallel.
In addition to specifying markup, HTML5 specifies scripting application programming interfaces (APIs). Existing document object model (DOM) interfaces are extended and de facto features documented. There are also new APIs, such as:
- The canvas element for immediate mode 2D drawing
- Timed media playback
- Offline storage database (offline web applications)
- Document editing
- Cross-document messaging (web messaging)
- Browser history management
- MIME type and protocol handler registration