HTML
HTML stands for Hypertext Markup Language
HTML is the standard markup language for creating Web pages . HTML describes the structure of a Web page
CSS
CSS stands for Cascading Style Sheets
CSS describes how HTML elements are to be displayed on screen, paper, or in other media CSS saves a lot of work.
It can control the layout of multiple web pages all at once
PHP
PHP is an acronym for "Hypertext Preprocessor"
PHP is a widely-used, open source scripting language. PHP scripts are executed on the server. PHP is free to download and use
Javascript
JavaScript is the world's most popular programming language. JavaScript is the programming language of the Web. JavaScript is easy to learn.