JavaScript engines were originally used only in web browsers, but are now core components of some servers and a variety of applications. The most popular runtime system for this usage is Node.js.
Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for the appearance of the document.
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).
The frontend is the content management application. It enables writers, editors, and project managers to work seamlessly without the need to code. The backend is the content delivery application, which is used for publishing and displaying the content in various formats based on the CMS.