HTML: Hypertext Markup Language, a standardized system for tagging text files to achieve font, colour, graphic, and hyperlink effects on World Wide Web pages. CSS: A cascading style sheet (CSS) is a Web page derived from multiple sources with a defined order of precedence where the definitions of any style element conflict. JavaScript: JavaScript is an interpreted programming or script language from Netscape. ... In general, script languages are easier and faster to code in than the more structured and compiled languages such as C and C++. ... JavaScript uses some of the same ideas found in Java, the compiled object ... Jquary: jQuery is a cross-platform JavaScript library designed to simplify the client-side scripting of HTML. jQuery is the most popular JavaScript library in use today, with installation on 65% of the top 10 million highest-trafficked sites on the Web. jQuery is free, open-source software licensed under the MIT License. Ajax: Ajax is a client-side script that communicates to and from a server/database without the need for a postback or a complete page refresh. The best definition I've read for Ajax is �the method of exchanging data with a server, and updating parts of a web page - without reloading the entire page.�