JavaScript is a high level, often just in time compiled language that conforms to the ECMAScript standard. It has dynamic typing, prototype based object orientation, and first class functions. It is multi paradigm, supporting event driven, functional, and imperative programming styles. It has application programming interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document Object Model (DOM).
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript.
In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL.
Web Development and Content Management Systems Rely on PhP, HTML, Javascript, MySQL and CSS to function. These are the most common languages in modern Web Development.