HTML5

HTML5 (Hypertext Markup Language 5) is a markup language used for structuring and presenting hypertext documents on the World Wide Web. It was the fifth and final major HTML version that is now a retired World Wide Web Consortium (W3C) recommendation.
HTML5 was first released on January 22, 2008, with a major update and "W3C Recommendation" status in October 2014. Its goals were to improve the language with support for the latest multimedia and other new features. It is also aimed to keep the language both easily readable by humans and consistently understood by computers and devices such as web browsers, parsers, etc., without XHTML's rigidity; and to remain backward-compatible with older software. HTML5 is intended to subsume not only HTML 4 but also XHTML1 and even the DOM Level 2 HTML itself.HTML5 differences from HTML4
==Features==
===New features===
To extend HTML, HTML5 features new tags, such as <video>, <audio> and <canvas>. Expandable sections are natively implemented through <summary>...</summary> and <details>...</details> rather than depending on CSS or JavaScript.
Features to support for scalable vector graphics (SVG) content and MathML for mathematical formulas was also added.
New page structure elements are added to enrich the semantic content of documents: <main>, <article>, <header>, <footer>, <aside>, <nav>, and <figure>.
New attributes were introduced, some elements and attributes were removed, and others such as <a>, , and <menu> were changed, redefined, or standardized.
The APIs and Document Object Model (DOM) are now fundamental parts of the HTML5 specification, and HTML5 also better defines the processing for any invalid documents.
===Markup===
HTML5 introduces elements and attributes that reflect typical usage on modern websites. Some of them are semantic replacements for common uses of generic block and inline elements. For example, to display audio and video, <video> and <audio> are used instead of <object>https://web.archive.org/web/20110124043555/http://dev.opera.com/articles/view/introduction-html5-video/
Some deprecated elements from HTML 4.01 have been dropped, including purely presentational elements such as and , whose effects have long been superseded by Cascading Style Sheets, a programming language used to enhance web design.
The HTML5 syntax is no longer based on SGML despite the similarity of its markup. However, It has been designed to be backward-compatible with common parsing of older versions of HTML. It comes with a new introductory line that looks like an SGML document type declaration, <!DOCTYPE html>, which triggers the standards-compliant rendering mode.
Since January 5, 2009, HTML5 also includes Web Forms 2.0, a previously separate WHATWG specification. obsolescence notice
===New APIs===
In addition to its markup format, HTML5 specifies scripting application programming interfaces (APIs) that can be used with JavaScript.https://html-differences.whatwg.org/#syntax Existing Document Object Model (DOM) interfaces are extended and actual features which are not mentioned are documented. HTML5 also introduces new APIs, such as:{{Cite web|url=https://html.spec.whatwg.org/multipage/interaction.html#dnd|title=HTML|work=whatwg.org}]
*Canvas
*Timed Media Playback
*Offline
*Editable content
*Drag and drop
*History
*MIME type and protocol handler registration
*Microdata
*Web Messaging
*Web Storage
Some APIs are not part of either the W3C HTML5 or the WHATWG HTML specification. The W3C publishes specifications for these separately as follows:
* Geolocation;
* IndexedDB – an indexed hierarchical key-value store (formerly WebSimpleDB);
* File API – an API intended to handle file uploads and file manipulation;
* Directories and System – an API intended to satisfy client-side-storage use cases not well served by databases;
* File Writer – an API for writing to files from web applications;<
* Web Audio – a high-level JavaScript API for processing and synthesizing audio in web applications;
* ClassList.
* Web cryptography API
* WebRTC
* Web SQL Database – a local SQL Database (no longer maintained)
==Versions==
Here is the list of versions of HTML5:
Version 	First draft 	Candidate recommendation	Recommendation 	Retired
HTML5 	1 May 2007 	17 December 2012 	28 October 2014 	27 March 2018
HTML 5.1 	17 December 2012	21 June 2016 	1 November 2016 	28 January 2021
HTML 5.1 2nd Edition	N/A 	20 June 2017 	3 October 2017 	28 January 2021
HTML 5.2 	18 August 2016 	8 August 2017 	14 December 2017	28 January 2021
HTML 5.3 	14 December 2017	N/A 	N/A 	
==See Also==
*HTML5 in Wikipedia.
==External links==
* HTML Living standard from WHATWG, GitHub repo
* The W3C Markup Validation Service, including Nu Html Checker
* HTML 5.2, the last HTML recommendation from W3C, superseded
* Memorandum of Understanding Between W3C and WHATWG
* HTML Media Extensions Working Group
* HTML.next, Feature requests for future versions of HTML
==References==