HTML, CSS and JavaScript

HTML is the basic building block of all websites. HTML stands for HyperText Markup Language. HyperText is something advanced than simple text, it means plain text embedded with other media types like images, flash animations etc. HTML was the idea of Tim Berners-Lee and is based on SGML (Standard Generalized Mark-up Language) which was used earlier for the same purpose. HTML is the claimed standard for web page display and currently its development is supported by the World Wide Web Consortium (W3C). HTML is organised in form of tags. Some tags belong to the header and others to the body. The most used header tags are title, meta-tags(description, keywords etc.). The body contains tag used for display of hypertext and that too with correct formatting. HTML is now slowly replaced by a better alternative known as XHTML which is a fusion of HTML and XML.

CSS stands for Cascaded Style Sheet, a recent development in the field of web technologies. CSS is the stylesheet information attached to the HTML pages and provide information about the look and feel of the webpage. It replaces the default styles attached with the tags in a page, set by the browser, with values given by the web designer. For example if you want to change the color of the visited links from purple to some other color or you want an 'on hovering' effect etc. Current implemented Specification of CSS is 2 in Internet Explorer 7 and Mozilla Firefox also supports CSS 3 to some extent.

JavaScript is a Client-side scripting language which in simple words means its a programming lanuage which is compiled (rather interpreted) by the browser at runtime. JavaScript is very similar to C Programming lanuage. JavaScript was developed by Netscape and it has absolutely no relation with Java developed by Sun. It derives its name JavaScript due to a co-marketing deal between Netscape and Sun. Javascript is used for making the website dynamic. Since it is processed at the client side, so it does not require resources from the server and hence prevents the server from overload and also the user relieves from loading time of content from the server. Use of Javascript has increased considerably over the last few years. Now most of the site implement one or the other use of Javascript for their website. For example - showing popups, verifying form fields, showing some mouse over effects etc. Also, many website today use AJAX which is an implementaion of Javascript.