Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript.
Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for its appearance.
HTML elements are the building blocks of HTML pages. With HTML constructs, images and other objects such as interactive forms may be embedded into the rendered page. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes, and other items. HTML elements are delineated by tags, written using angle brackets. Tags such as <img> and <input> directly introduce content into the page. Other tags such as <p> surround and provide information about document text and may include sub-element tags. Browsers do not display the HTML tags but use them to interpret the content of the page.
HTML can embed programs written in a scripting language such as JavaScript, which affects the behavior and content of web pages. The inclusion of CSS defines the look and layout of content. The World Wide Web Consortium (W3C), former maintainer of the HTML and current maintainer of the CSS standards, has encouraged the use of CSS over explicit presentational HTML since 1997. A form of HTML, known as HTML5, is used to display video and audio, primarily using the <canvas> element, together with JavaScript.
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 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.
Another important component is the HTML document type declaration, which triggers standards mode rendering.
The following is an example of the classic “Hello, World!” program:
<!DOCTYPE html>
<html>
<head>
<title>This is a title</title>
</head>
<body>
<div>
<p>Hello world!</p>
</div>
</body>
</html>
The text between <html> and </html> describes the web page,
and the text between <body> and </body> is the visible page content.
The markup text <title>This is a title</title> defines the browser page title shown on tabs and window titles,
and the tag <div> defines a division of the page used for easy styling.
Header of the HTML document:
<head>
<title>The Title</title>
<link rel="stylesheet" href="stylebyjimbowales.css"> <!-- Imports Stylesheets -->
</head>
HTML headings are defined with the <h1> to <h6> tags:
<h1>Heading level 1</h1>
<h2>Heading level 2</h2>
<h3>Heading level 3</h3>
<h4>Heading level 4</h4>
<h5>Heading level 5</h5>
<h6>Heading level 6</h6>
The effects are:
In 1980, physicist Tim Berners-Lee, a contractor at CERN, proposed and prototyped ENQUIRE, a system for CERN researchers to use and share documents. In 1989, Berners-Lee wrote a memo proposing an Internet-based hypertext system. Berners-Lee specified HTML and wrote the browser and server software in late 1990. That year, Berners-Lee and CERN data systems engineer Robert Cailliau collaborated on a joint request for funding, but the project was not formally adopted by CERN.
The first publicly available description of HTML was a document called "HTML Tags". It describes 18 elements comprising the initial, relatively simple design of HTML. Except for the hyperlink tag, these were strongly influenced by SGML-based documentation format at CERN.
November 24, 1995
HTML 2.0 was published as RFC 1866. Supplemental RFCs added capabilities:
January 14, 1997
HTML 3.2 was published as a W3C Recommendation. It adopted many of Netscape's visual markup tags and deprecated others.
December 18, 1997
HTML 4.0 was published as a W3C Recommendation. It offers three variations: