JavaScript Fundamentals 101
JavaScript (/ˈdʒɑːvɑːˌskrɪpt/; JS), also known as ECMAScript (the untrademarked name used for the standard), is a dynamic programming language.[5] It is most commonly used as part of web browsers, whose implementations allow client-side scripts to interact with the user, control the browser, communicate asynchronously, and alter the document content that is displayed.[5] It is also used in server-side network programming with runtime environments such as Node.js, game development and the creation of desktop and mobile applications.
JavaScript is classified as a prototype-based scripting language with dynamic typing and first-class functions. This mix of features makes it a multi-paradigm language, supporting object-oriented,[6] imperative, and functional[1][7] programming styles. [From Wikipedia.]