https://html.spec.whatwg.org/multipage/ is the canonical HTML specification.
HTML (HyperText Markup Language) is the primary markup language for creating web pages and other information to be displayed to humans in a web browser.
It was invented by Sir Tim Berners-Lee while developing the first Web browser at CERN to enable researchers to share their findings and was formally released in June 1993. The original "HTML Tags" were first publicly mentioned by Berners-Lee in 1991 and borrowed the syntax from CERN's SGML-based documentation standard. The latest and current version for HTML is HTML5.3.
HTML is a hierarchical (tree-structured) markup language. That is, an item might descend from another item, which is its ancestor. However, if item2 is a descendant of item1, they have an additional special relation: item2 is inside of item1, or item1 is wrapped around item2.
HTML is written in the form of elements consisting of tags (and their attributes) enclosed in angle brackets (e.g.,
HTML attributes are most commonly expressed in a
key="value" format. However, there are exceptions in which some attributes can be written with no value and still be interpreted.
HTML tags most commonly come in pairs. The first is known as the opening tag and the second, which includes a forward slash, is the closing tag (e.g.,
</h1>). Various types of content, such as text or additional HTML elements, can be contained within these tags. Some tags, however, are unpaired, and these are known as empty elements or self-closing tags. They may or may not include the slash (e.g.,
Collectively, these tags form an HTML document. Web browsers read these documents, interpret each HTML tag, and then render their corresponding visual and/or audible display in the form of a web page.
HTML standards, as well as those for many other web technologies, are maintained by the World Wide Web Consortium (W3C).
HTML4 was introduced in 1997, and the latest iteration, HTML5, was recently developed by the W3C. What W3C calls HTML5 is a subset, with a few modifications, of the HTML-Living-Standard, which is specified by the Web Hypertext Application Technology Working Group (WHATWG).
The language specification and standards documents for HTML5 are available online.
Design and Scripting
HTML markups are designed, or 'styled', via CSS (Cascading Style Sheets), using one or more of the following:
<link>tag, which loads a CSS file
<style>tag, where CSS rules are defined
styleattribute of HTML tags, where inline styles can be specified
<script>tag with an
srcattribute, which points to a script file
- event attributes of HTML tags, like
- W3C HTML/Specifications
- W3C HTML Validator
- HTML Reference at the Mozilla Developer Network (MDN)
- Microsoft Edge Developer website
- SitePoint HTML Reference
- Way2Tutorial HTML Reference
- MDN Learning Area
- W3C Web Content Accessibility Guidelines
- HTML Feature Requests
- HTML5 Reference
Free HTML Books:
HTML5: What’s New?