Key difference: HTML5 is the fifth revision of the HTML standard. HTML stands for HyperText Markup Language. It is a well known mark up language used to develop web pages. The core aims of HTML5 have been to improve the language with support for the latest multimedia. jQuery, on the other hand, is a multi-browser JavaScript library. jQuery is a free, open source software. It is licensed under the MIT License. It was designed to simplify the client-side scripting of HTML and is currently used by numerous websites.

HTML5 is the fifth revision of the HTML standard. HTML stands for HyperText Markup Language. It is a well known mark up language used to develop web pages. It has been around for a long time and is commonly used in webpage design. XML or Extensible Markup Language defines a set of rules for encoding documents in a format that can be read by both, human and computer.

HTML is written using HTML elements, which consist of tags, primarily and opening tag and a closing tag. The data between these tags is usually the content. The main objective of HTML is to allow web browsers to interpret and display the content written between the tags. The tags are designed to describe the page content. HTML comes with predefined tags. They allow one to insert images, text, videos, forms and other pieces of content together into a cohesive webpage.

Elements of HTML are the basic building blocks of all websites. HTML allows images and objects to be embedded in the webpage. It can also be used to create interactive forms. HTML also provides the means to create structured documents. It does this by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes and other items. However these days, web pages are rarely designed using only HTML. HTML allows for the programmer to embed scripts written in languages such as JavaScript, which many often do. This changes the look and behavior of the HTML web pages.

The core aims of HTML5 have been to ‘improve the language with support for the latest multimedia while keeping it easily readable by humans and consistently understood by computers and devices, such as web browsers, parsers, etc.’ HTML5 supercedes HTML 4, as well as XHTML 1 and DOM Level 2 HTML. Additionally, as of December 2012, HTML5 is W3C Candidate Recommendation.

HTML5 aimed to address the variety of mixture of features introduced by various specifications by various browsers. It also aimed to address the many syntax errors in existing web documents. Additionally, it attempts to define a single markup language that can be written in either HTML or XHTML syntax. It is also backward compatible with the previous HTML versions.

jQuery, on the other hand, is a multi-browser JavaScript library. jQuery is a free, open source software. It is licensed under the MIT License. It was designed to simplify the client-side scripting of HTML and is currently used by numerous websites. In fact, according to Wikipedia, it is used by over 55% of the 10,000 most visited websites. It is the most popular JavaScript library in use today. jQuery was released in January 2006 at BarCamp NYC by John Resig. However, it is currently developed by a team of developers led by Dave Methvin.

jQuery's syntax is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications. In addition to the JavaScript library, jQuery also provides capabilities for developers to create plug-ins. The advantage of this is that it enables developers to create abstractions for low-level interaction and animation, advanced effects and high-level, theme-able widgets. Furthermore, the approach to the jQuery library allows the creation of powerful dynamic web pages and web applications.

jQuery also makes HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers.

The main difference between HTML and jQuery is that jQuery is a JavaScript framework, a JavaScript library. Whereas, HTML5 is the latest version of HTML; it is a for the HTML structure/presentation. 

Image Courtesy: w3.org, dochub.io